A135540 - OEIS

%I #9 Oct 19 2016 03:04:43

%S 1,3,1,7,3,3,1,15,7,7,3,7,3,3,1,31,15,15,7,15,7,7,3,15,7,7,3,7,3,3,1,

%T 63,31,31,15,31,15,15,7,31,15,15,7,15,7,7,3,31,15,15,7,15,7,7,3,15,7,

%U 7,3,7,3,3,1,127,63,63,31,63,31,31,15,63,31,31,15,31,15,15,7,63,31,31,15,31,15

%N a(n) = 2^(A000523(n) - A000120(n) + 2) - 1.

%H G. C. Greubel, <a href="/A135540/b135540.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = 2^(floor(log_2(n)) - (n - Sum_{k=1,..,n}[floor(n/2^k)]) + 2) - 1. - _G. C. Greubel_, Oct 18 2016

%p GS(6,3,200); [see A135416].

%t Table[2^(Floor[Log[2, n]] - (n - Sum[Floor[n/2^k], {k, 1, n}]) + 2) - 1, {n,1,25}] (* _G. C. Greubel_, Oct 18 2016 *)

%Y Cf. A135416.

%Y This is Guy Steele's sequence GS(6, 3) (see A135416).

%K nonn

%O 1,2

%A _N. J. A. Sloane_, based on a message from Guy Steele and _Don Knuth_, Mar 01 2008