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A227834
2^a(n) is the highest power of 2 dividing A000930(n).
2
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
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
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 04 2013
STATUS
approved