A227834 2^a(n) is the highest power of 2 dividing A000930(n).

0, 0, 0, 1, 0, 2, 1, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 1, 0, 3, 1, 0, 0, 0, 3, 0, 3, 7, 0, 0, 0, 1, 0, 2, 1, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 1, 0, 4, 1, 0, 0, 0, 4, 0, 4, 6, 0, 0, 0, 1, 0, 2, 1, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 1, 0, 3, 1, 0, 0, 0, 3, 0, 3, 6, 0, 0, 0, 1, 0, 2, 1, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 1, 0, 5, 1, 0, 0, 0, 5, 0, 5, 7, 0

Offset

0,6

Comments

This is the 2-adic valuation of A000930.

Links

G. C. Greubel, Table of n, a(n) for n = 0..5000

Mathematica

A000930[n_] := Sum[Binomial[n - 2*i, i], {i, 0, Floor[n/3]}];
Table[IntegerExponent[A000930[n], 2], {n, 0, 100}] (* G. C. Greubel, Apr 26 2017 *)

Prog

(Magma) A000930:=func<i | &+[Binomial(i-2*k, k): k in [0..i div 3]]>; [Valuation(A000930(n), 2): n in [0..120]]; // Bruno Berselli, Aug 05 2013

Crossrefs

Cf. A000930, A007814, A227835.

Sequence in context: A211996 A359326 A352245 * A025894 A339087 A051127

Adjacent sequences: A227831 A227832 A227833 * A227835 A227836 A227837

Keyword

nonn

Author

N. J. A. Sloane, Aug 04 2013

Status

approved