## Prime factors of n15+1

### Problem 421

Published on Sunday, 31st March 2013, 04:00 am; Solved by 212

Numbers of the form n15+1 are composite for every integer n 1.
For positive integers n and m let s(n,m) be defined as the sum of the distinct prime factors of n15+1 not exceeding m.

E.g. 215+1 = 3311331.
So s(2,10) = 3 and s(2,1000) = 3+11+331 = 345.
Also 1015+1 = 7111321124121619091.
So s(10,100) = 31 and s(10,1000) = 483.

Find ∑ s(n,108) for 1 n 1011.