25 May
2008
25 May
'08
4:01 a.m.
We could solve NP problems if we had an efficient way to calculate either a) F(N,D) = sum(1<=n<=N, 1<=d<=D) floor[n/d] or b) G(N,D) = sum(1<=n<=N) #{ divisors d of N such that 1<=d<=D } "Efficient" means polynomial in the logs of N and D. It's not obvious to me that we could solve these problems even with an NP (or #P) oracle, so perhaps they are stronger than NP. Rich