A227835 3^a(n) is the highest power of 3 dividing A000930(n).

0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 0, 1, 0, 1, 3, 0, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 0, 1, 0, 1, 3, 0, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 0, 1, 0, 1, 4, 0, 0, 0, 0, 3, 0, 3, 4, 0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 0, 1, 0, 1, 3, 0, 0, 0, 0, 2, 0, 2, 3, 0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 0, 1, 0, 1, 3, 0

Offset

0,8

Comments

This is the 3-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], 3], {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), 3): n in [0..120]]; // Bruno Berselli, Aug 05 2013

Crossrefs

Cf. A000930, A007949, A227834.

Sequence in context: A330733 A328496 A035202 * A281154 A245536 A291203

Adjacent sequences: A227832 A227833 A227834 * A227836 A227837 A227838

Keyword

nonn

Author

N. J. A. Sloane, Aug 04 2013

Status

approved