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%I #2 Mar 30 2012 16:51:05
%S 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,
%T 54,100,142,112,48,10,6,16,16,18,40,50,30,20,40,50,54,100,142,112,48,
%U 22,40,50,54,100,142,112,72,102,142,160,256,386,368,210,70,12,6,16,16,18,40,50
%N a(n) = sum_{k >= 1} 2^wt(k) * binomial(wt(n+k),k).
%p wt := proc(n) local w,m,i;
%p w := 0; m := n; while m > 0 do i := m mod 2; w := w+i; m := (m-i)/2; od; w; end:
%p f := n->add( 2^k*binomial(wt(n+k),k),k=1..20 );
%Y Cf. A151685, A151690.
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Jun 04 2009
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