Hi guys! I've encountered a problem which basically narrows down to finding f(x) fast, where f(x) is the number of palindromes less than X. For argument sake let's say you have to answer q queries about f(x), with q <= 10^6 and x <= 10^9. I've been struggling to find a solution, so any help would be appreciated.

Hi guys! I've come across a problem which asks for the number of divisors of C(n) = n * ( 2 ^ n ) + 1, with n <= 60. Can anyone find a fast solution for it?