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A117415
E.g.f. (x*tan(x)-x^2)/8 (even powers only).
1
0, 0, 1, 12, 272, 9920, 530688, 39144448, 3807514624, 472197021696, 72722212782080, 13616619646091264, 3046271659520557056, 802494810618175946752, 245880605613803859607552, 86696940704285991905525760, 34855851028500677184683245568
OFFSET
0,4
FORMULA
a(n) = 2^(2*n-1) * (2^(2*n)-1) * abs(Bernoulli(2*n))/4 - (C(1,n) - C(0,n))/4.
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[(x*Tan[x]-x^2)/8, {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 06 2014 *)
CROSSREFS
Column k=2 of Euler triangle A117414.
Sequence in context: A107485 A293270 A341815 * A377526 A152129 A115461
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Mar 13 2006
EXTENSIONS
More terms from Harvey P. Dale, May 06 2014
STATUS
approved