A151689 a(n) = sum_{k >= 1} 2^wt(k) * binomial(wt(n+k),k).

2, 6, 4, 6, 16, 16, 6, 6, 16, 16, 18, 40, 50, 30, 8, 6, 16, 16, 18, 40, 50, 30, 20, 40, 50, 54, 100, 142, 112, 48, 10, 6, 16, 16, 18, 40, 50, 30, 20, 40, 50, 54, 100, 142, 112, 48, 22, 40, 50, 54, 100, 142, 112, 72, 102, 142, 160, 256, 386, 368, 210, 70, 12, 6, 16, 16, 18, 40, 50

Offset: 0

Author

N. J. A. Sloane, Jun 04 2009

Keywords

• nonn

Crossrefs

Cf. A151685, A151690.

Programs

Maple

wt := proc(n) local w,m,i;
w := 0; m := n; while m > 0 do i := m mod 2; w := w+i; m := (m-i)/2; od; w; end:
f := n->add( 2^k*binomial(wt(n+k),k),k=1..20 );