A319922 Number of ways of writing n as a sum of exactly 10 powers of 2.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 6, 5, 6, 6, 7, 8, 9, 8, 10, 9, 10, 11, 13, 11, 14, 12, 13, 12, 15, 12, 16, 14, 16, 14, 18, 15, 19, 17, 21, 18, 22, 17, 22, 18, 22, 19, 25, 19, 24, 20, 25, 21, 28, 21, 27, 21, 26, 19, 27, 20, 26, 19

Offset: 0

Author

Alois P. Heinz, Oct 01 2018

Keywords

• nonn
• look

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..65536

Crossrefs

Column k=10 of A089052.

Cf. A000079.

Programs

Maple

h:= proc(n) option remember; `if`(n<1, 0,
      `if`(n=2^ilog2(n), n, h(n-1)))
    end:
b:= proc(n, i, k) option remember; `if`(n=0, `if`(k=0, 1, 0), `if`(
      k>n or i*k b(n, h(n), 10):
seq(a(n), n=0..120);

Formula

a(n) = [x^n y^10] 1/Product_{j>=0} (1-y*x^(2^j)).