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A166231 a(n) = 2^C(n+1,2)*A006012(n). 4
1, 4, 48, 1280, 69632, 7602176, 1660944384, 725849473024, 634418209226752, 1109011408239984640, 3877275019992826380288, 27111105978154633171828736, 379138479844261543254652092416, 10604214183559196000870296488771584 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Hankel transform of A166228, A166229.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..70

FORMULA

a(n) = 2^C(n+1,2)*Sum_{k=0..floor(n/2)} C(n,2k)*2^(n-k).

a(n) = 4^n*A166232(n).

MATHEMATICA

Table[2^(Binomial[n + 1, 2])*Sum[Binomial[n, 2 k]*2^(n - k), {k, 0, Floor[n/2]}], {n, 0, 25}] (* G. C. Greubel, May 07 2016 *)

CROSSREFS

Cf. A006012, A166228, A166229, A166232.

Sequence in context: A296838 A211049 A321076 * A191952 A013145 A013150

Adjacent sequences:  A166228 A166229 A166230 * A166232 A166233 A166234

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Oct 09 2009

STATUS

approved

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Last modified January 22 07:39 EST 2020. Contains 331139 sequences. (Running on oeis4.)