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A151689
a(n) = sum_{k >= 1} 2^wt(k) * binomial(wt(n+k),k).
2
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
0,1
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 );
CROSSREFS
Sequence in context: A240751 A212283 A247566 * A216833 A242046 A330776
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 04 2009
STATUS
approved