add code

19 files changed, 543 insertions, 0 deletions

diff --git a/10001prime.py b/10001prime.py
new file mode 100644
index 0000000..ecf8139
--- /dev/null
+++ b/10001prime.py
@@ -0,0 +1,31 @@
+import PIL, math
+import numpy as np
+
+#Problem 7 - 10,001st prime
+
+#returns a list of every prime up to a certain number
+def listprimes(number):
+	primes = []
+	if (number <=1):
+		return [1]
+	a = np.ones(number)
+	a[0]=0
+	a[1]=0#1 and 0 are not prime
+	##Sieve of eratosthenes
+	for i in range(2,int(math.ceil(math.sqrt(number)))):
+		if(a[i]==1):
+			j = i**2 #cross out all the multiples of i, starting with its square
+			while(j < number):
+				a[j] = 0
+				j+=i
+	
+	for k in range(2, number):
+		#is prime
+		if(a[k]==1):
+			primes.append(k)
+	return primes
+
+out_list = listprimes(1000000)
+print out_list
+#return 10,001th prime factor
+print out_list[10000]
diff --git a/bigfactors2.py b/bigfactors2.py
new file mode 100644
index 0000000..5758019
--- /dev/null
+++ b/bigfactors2.py
@@ -0,0 +1,31 @@
+import PIL, math
+import numpy as np
+
+#Problem 12 Highly divisible triangular number
+#finds the first number with over 500 factors
+
+def countfactors(num):
+	factors = 0
+	### we only need to know about the FIRST HALF of factors,
+	##one factor implies a second
+	root = int(math.ceil(math.sqrt(num)))
+	divs = range(1, root)
+	for d in divs:
+		if(num%d == 0):
+			factors += 2
+			
+	#Correction if the number is a perfect square
+	if (root * root == num):
+		factors-=1
+	return factors
+
+
+####   MAIN #####
+i=1
+k=1
+j = 0
+while(k < 500):
+	j += i
+	k=countfactors(j)
+	print str(j) + " has " + str(k) + " factors"
+	i += 1
diff --git a/collatz.py b/collatz.py
new file mode 100644
index 0000000..1052610
--- /dev/null
+++ b/collatz.py
@@ -0,0 +1,25 @@
+import PIL, math
+import numpy as np
+
+#Problem 14 Longest Collatz sequence
+#Note, a little slow, takes about 15 seconds. 
+#There is probably a more efficient solution out there
+chain = []
+biggo = []
+
+def collatz(seed):
+	chain.append(seed)
+	if(seed == 1): return 0
+	if(seed%2 == 0):
+		seed = seed/2
+	else:
+		seed = 3*seed +1
+	collatz(seed)
+
+for n in range(1,pow(10,6)):
+	collatz(n)
+	if(len(chain)>len(biggo)):
+		biggo = chain
+	chain = []
+print biggo
+print "Has " + str(len(biggo)) +" numbers."
diff --git a/euler1 b/euler1
new file mode 100755
index 0000000..585d380
--- /dev/null
+++ b/euler1
diff --git a/euler1.c b/euler1.c
new file mode 100644
index 0000000..d89956e
--- /dev/null
+++ b/euler1.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include <stdlib.h>
+//Problem 1: multiples of 3 and 5
+int main(){
+	int max = 1000;
+	int i; double sum;
+	
+	for (i=0;i<max; i++)
+		if(i%3 == 0 || i%5==0)
+			 sum+= (double) i;
+	
+	printf("%f\n", sum);
+}
diff --git a/euler1.o b/euler1.o
new file mode 100644
index 0000000..2abffe6
--- /dev/null
+++ b/euler1.o
diff --git a/fib.py b/fib.py
new file mode 100644
index 0000000..77b32fa
--- /dev/null
+++ b/fib.py
@@ -0,0 +1,33 @@
+import PIL, math
+MAX = 4*10**6
+
+#Problem 2 Even Fibonnacci numbers
+fib = [1, 1]
+
+k=1;
+while (True):
+	n = fib[k] + fib[k-1]
+	if(n>MAX):
+		break
+	else:
+		fib.append(n);
+		k+=1
+
+c=0
+for i in fib:
+	num = str(i)
+	print(num + " ", end='')
+	c+=1
+	if(c%10==0):
+		print()
+	
+print()
+
+print("The sum is: " + str(sum(fib)))
+
+s=0
+for i in fib:
+	if (i%2==0):
+		s+=i
+
+print("The sum of the even terms is: " + str(s))
diff --git a/largestprime.py b/largestprime.py
new file mode 100644
index 0000000..fa39904
--- /dev/null
+++ b/largestprime.py
@@ -0,0 +1,55 @@
+import PIL, math
+import numpy as np
+#Problem 3 Largest Prime Factor
+
+###INEFFICIENT METHODS###
+#def isPrime(number):
+#	if (number <=1):
+#		return False
+#	for i in range(2,number):
+#		if(number%i==0):
+#			return False
+#	return True
+
+#def prime_factors(number):
+	#primes = []
+	#for i in range(number, 2, -1):
+		#if(number%i==0):
+			#if (isPrime(i)):
+				#return i
+	#return primes
+
+
+
+def prime_factors(number):
+	primes = []
+	if (number <=1):
+		return [1]
+	a = np.ones(number)
+	a[0]=0
+	a[1]=0#not prime
+	for i in range(2,int(math.ceil(math.sqrt(number)))):
+		if(a[i]==1):
+			j = i**2 #cross out all the multiples
+			while(j < number):
+				a[j] = False
+				j+=i
+	
+	for k in range(2, number):
+		#is prime		is a factor
+		if(a[k]==1) and (number%k==0):
+			primes.append(k)
+	return primes
+	
+def lpf(number):
+	factor = 2
+	while (number > factor):
+		if(number % factor == 0):
+			number = number/factor
+			factor = 2
+		else:
+			factor +=1
+	return factor
+			
+out = lpf(600851475143)
+print out
diff --git a/palindrome.py b/palindrome.py
new file mode 100644
index 0000000..c581a72
--- /dev/null
+++ b/palindrome.py
@@ -0,0 +1,41 @@
+import PIL, math
+import numpy as np
+
+#Problem 4 - Palindrome Products
+
+def isPalindrome(number):
+	numchar = str(number)
+	middle = len(numchar)/2
+	face = numchar[:middle]
+	ref = numchar[len(numchar):middle-1:-1]
+	if(face == ref):
+		return True
+	else:
+		return False
+
+def findProduct(number):
+	for i in range(999,100,-1):
+		for j in range(999,100,-1):
+			if(i*j==number):
+				return [i,j]
+			
+def findMaxPalindrome():
+	large = 0
+	for i in range(999,100,-1):
+		for j in range(999,100,-1):
+			test = i*j
+			if(isPalindrome(test) and test > large):
+				large = test
+	return large
+
+answer = findMaxPalindrome()
+print answer
+print "The factors are: " + str(findProduct(answer))
+#x = input("Type a palindromic number: ")
+
+#if(isPalindrome(x)):
+	#print "The factors are: " + str(findProduct(x))
+#else:
+	#print "not a palindrome"
+
+			
diff --git a/prodgrid b/prodgrid
new file mode 100755
index 0000000..5054666
--- /dev/null
+++ b/prodgrid
diff --git a/prodgrid.c b/prodgrid.c
new file mode 100644
index 0000000..a4f27c3
--- /dev/null
+++ b/prodgrid.c
@@ -0,0 +1,87 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+//Problem 11 - Largest Product in a grid
+
+int matrix[20][20]= {{8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8},
+					{49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0},
+					{81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65},
+					{52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91},
+					{22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},
+					{24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},
+					{32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},
+					{67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21},
+					{24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},
+					{21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95},
+					{78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92},
+					{16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57},
+					{86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},
+					{19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40},
+					{4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},
+					{88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},
+					{4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36},
+					{20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16},
+					{20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54},
+					{1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48}};
+
+int parseMatrix(int mat[20][20]){
+	int maxi, i, j, k, c = 0;
+	int prod = 1;
+	//parse left to right
+	for(i; i < 20; i++){
+		for(j; j < 16; j++){
+			k = j;
+			prod = 1;
+			for(k; k<j+4; k++){
+				prod*=mat[i][k];
+				if(prod > maxi)
+					maxi=prod;
+			}
+		}
+	}
+	//parse up and down
+	for(j=0; j < 20; j++){
+		for(i=0; i < 16; i++){
+			k = i;
+			prod = 1;
+			for(k; k < i+4; k++){
+				prod*=mat[k][j];
+			if(prod > maxi)
+				maxi=prod;
+			}
+		}
+	}
+	
+	//parse diagonal right
+	for(i=0; i < 16; i++){
+		for(j=0; j < 16; j++){
+			prod = 1;
+			for(c = 0; c < 4; c++){
+				prod*=mat[i+c][j+c];
+			if(prod > maxi)
+				maxi=prod;
+			}
+		}
+	}
+	
+	//parse diagonal left
+	for(i=0; i < 16; i++){
+		for(j=19; j > 3; j--){
+			prod = 1;
+			for(c = 0; c < 4; c++){
+				prod*=mat[i+c][j-c];
+			if(prod > maxi)
+				maxi=prod;
+			}
+		}
+	}
+
+	return maxi;
+}
+
+
+int main(){
+	int ans = parseMatrix(matrix);
+	printf("%d\n", ans);
+	return 0;
+}
diff --git a/prodgrid.c~ b/prodgrid.c~
new file mode 100644
index 0000000..611e036
--- /dev/null
+++ b/prodgrid.c~
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int matrix[20][20]= {{8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8},
+					{49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0},
+					{81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65},
+					{52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91},
+					{22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},
+					{24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},
+					{32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},
+					{67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21},
+					{24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},
+					{21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95},
+					{78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92},
+					{16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57},
+					{86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},
+					{19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40},
+					{04, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},
+					{88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},
+					{4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36},
+					{20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16},
+					{20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54},
+					{1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48}};
+
+int parseMatrix(int mat[20][20]){
+	int maxi, i, j, k, c = 0;
+	int prod = 1;
+	for(i; i < 20; i++){
+		for(j; j < 16; j++){
+			k = j;
+			prod = 1;
+			for(k; k<j+4; k++)
+				printf("(%d,%d)\n", i, k);
+				prod*=mat[i][k];
+			if(prod > maxi)
+				maxi=prod;
+		}
+	}
+	/*
+	for(j=0; j < 20; j++){
+		for(i=0; i < 16; i++){
+			k = i;
+			prod = 1;
+			for(k; k<k+4; k++)
+				prod*=mat[k][j];
+			if(prod > maxi)
+				maxi=prod;
+		}
+	}
+	for(i=0; i < 16; i++){
+		for(j=0; j < 16; j++){
+			prod = 1;
+			for(c = 0; c < 4; c++)
+				prod*=mat[i+c][j+c];
+			if(prod > maxi)
+				maxi=prod;
+		}
+	}
+	
+	for(i=0; i < 16; i++){
+		for(j=19; j > 0; j--){
+			prod = 1;
+			for(c = 0; c < 4; c++)
+				prod*=mat[i-c][j-c];
+			if(prod > maxi)
+				maxi=prod;
+		}
+	}
+	*/
+	return maxi;
+}
+
+
+int main(){
+	int ans = parseMatrix(matrix);
+	printf("%d\n", ans);
+	return 0;
+}
\ No newline at end of file
diff --git a/prodgrid.o b/prodgrid.o
new file mode 100644
index 0000000..bd2e679
--- /dev/null
+++ b/prodgrid.o
diff --git a/productofdigits.py b/productofdigits.py
new file mode 100644
index 0000000..d05b757
--- /dev/null
+++ b/productofdigits.py
@@ -0,0 +1,18 @@
+import PIL, math
+import numpy as np
+
+#Problem 8 - largest Product in a series
+def parseNum(x, r):
+	search = str(x)
+	maxi = 0
+	for ch in range(0,len(search)-r):
+		prod = int(search[ch])
+		for dig in range(ch+1, ch+r):
+			prod*=int(search[dig])
+		if (prod > maxi):
+			maxi = prod
+	return maxi
+			
+bigBoy=7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450
+
+print parseNum(bigBoy, 13)
diff --git a/productofgrid.py b/productofgrid.py
new file mode 100644
index 0000000..ab54c40
--- /dev/null
+++ b/productofgrid.py
@@ -0,0 +1,21 @@
+import PIL, math
+import numpy
+from numpy import matrix
+
+##Problem 11 - Largest Product in a grid
+def parseMatrix(x, r):
+
+	maxi = 0
+	for ch in range(0,len(search)-r):
+		prod = int(search[ch])
+		for dig in range(ch+1, ch+r):
+			prod*=int(search[dig])
+		if (prod > maxi):
+			maxi = prod
+	return maxi
+			
+#bigBoy=7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450
+
+mat = matrix([[08, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 08],[49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00],[81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65],[52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91],[22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],[24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],[32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],[67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 08, 40, 91, 66, 49, 94, 21],[24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],[21, 36, 23, 09, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95],[78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 09, 53, 56, 92],[16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57],[86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],[19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40],[04, 52, 08, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],[88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],[04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 08, 46, 29, 32, 40, 62, 76, 36],[20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16],[20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54],[01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48]])
+print mat[6,8]
+#print parseMatrix(mat, 4 )
diff --git a/smallmult.py b/smallmult.py
new file mode 100644
index 0000000..88c3dcc
--- /dev/null
+++ b/smallmult.py
@@ -0,0 +1,27 @@
+#Problem 5 smallest multiple
+#2520 is the smallest number that can be divided by 
+#each of the numbers from 1 to 10 without any remainder.
+#What is the smallest positive number that is evenly divisible 
+#by all of the numbers from 1 to 20?
+
+import PIL, math
+import numpy as np
+
+def isDivisible(num, divisors):
+	divisible = True
+	for j in divisors:
+		if(num%j !=0):
+			divisible = False
+			break
+	return divisible
+
+divs = range(1,21)
+
+found = False
+start = 2520
+while (not found):
+	start+=20
+	found = isDivisible(start,divs)
+	
+print start
+print str(isDivisible(start, divs))
diff --git a/sumexp.py b/sumexp.py
new file mode 100644
index 0000000..7e4a1f1
--- /dev/null
+++ b/sumexp.py
@@ -0,0 +1,10 @@
+import PIL, math
+#Problem 16 Power digit sum
+n = 2**1000
+strn = str(n)
+s = 0
+
+for i in strn:
+	s+=int(i)
+	
+print s
diff --git a/sumofprimes.py b/sumofprimes.py
new file mode 100644
index 0000000..7c1646b
--- /dev/null
+++ b/sumofprimes.py
@@ -0,0 +1,45 @@
+import PIL, math
+import numpy as np
+
+#Problem 10 sum of primes
+###INEFFICIENT###
+#def isPrime(number):
+#	if (number <=1):
+#		return False
+#	for i in range(2,number):
+#		if(number%i==0):
+#			return False
+#	return True
+
+#def prime_factors(number):
+	#primes = []
+	#for i in range(number, 2, -1):
+		#if(number%i==0):
+			#if (isPrime(i)):
+				#return i
+	#return primes
+
+
+
+def prime_factors(number):
+	primes = []
+	if (number <=1):
+		return [1]
+	a = np.ones(number)
+	a[0]=0
+	a[1]=0#not prime
+	for i in range(2,int(math.ceil(math.sqrt(number)))):
+		if(a[i]==1):
+			j = i**2 #cross out all the multiples
+			while(j < number):
+				a[j] = False
+				j+=i
+	
+	for k in range(2, number):
+		#is prime
+		if(a[k]==1):
+			primes.append(k)
+	return primes
+
+out = prime_factors(2000000)
+print str(sum(out))
diff --git a/sumsq.py b/sumsq.py
new file mode 100644
index 0000000..dd4e885
--- /dev/null
+++ b/sumsq.py
@@ -0,0 +1,28 @@
+#The sum of the squares of the first ten natural numbers is,
+#12 + 22 + ... + 102 = 385
+#The square of the sum of the first ten natural numbers is,
+#(1 + 2 + ... + 10)2 = 552 = 3025
+#Hence the difference between the sum of the squares 
+#of the first ten natural numbers and the square of the sum is 
+#Find the difference between the sum of the squares of the first 
+#one hundred natural numbers and the square of the sum.
+
+import PIL, math
+import numpy as np
+
+nums = range(1,11)
+numsq = range(1,11)
+
+for i in nums:
+	i = i*i
+
+print nums
+print numsq
+
+sum1 = (sum(nums)**2)
+sum2 = (sum(numsq))
+
+print "The sum squared is: " + str(sum1)
+print "The sum of the squares is: " + str(sum2)
+
+print "The difference is: " + str(abs(sum2-sum1))
\ No newline at end of file