MathDB

2014 Guts #21: Sum of Powers of Two Divisible by Five

Source:

April 21, 2014

Problem Statement

Compute the number of ordered quintuples of nonnegative integers

(a_1,a_2,a_3,a_4,a_5)

such that

0\leq a_1,a_2,a_3,a_4,a_5\leq 7

and

5

divides

2^{a_1}+2^{a_2}+2^{a_3}+2^{a_4}+2^{a_5}