# rozuur/peuler

### Subversion checkout URL

You can clone with HTTPS or Subversion.

Fetching contributors…

Cannot retrieve contributors at this time

66 lines (49 sloc) 1.312 kb
 /* The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be: 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ... Let us list the factors of the first seven triangle numbers: 1: 1 3: 1,3 6: 1,2,3,6 10: 1,2,5,10 15: 1,3,5,15 21: 1,3,7,21 28: 1,2,4,7,14,28 We can see that 28 is the first triangle number to have over five divisors. What is the value of the first triangle number to have over five hundred divisors? Ans: Find no of factors for all numbers till we get a triangular number with over 500 divisors. We can safely assume that max prime factor in that triangular numbers < 20 If F(n) = no of factors in n then F(n) = (c+1)*F(l) where n = p^(c+1) * l // p is smallest prime in n */ #include #define MAX 10000 int main() { int primes[]={2,3,5,7,11,13,17,19,0}; int factors[MAX]={0}; int i,j,c,n; factors[0]=factors[1]=1; factors[2]=factors[3]=2; for(i=4;i
Something went wrong with that request. Please try again.