A009150 - OEIS

A009150

Expansion of e.g.f. cosh(sin(x)^2) (even coefficients).

1, 0, 12, -240, 5712, -266880, 18566592, -1488963840, 141287377152, -16736203345920, 2412897423240192, -402658140395089920, 76287123858146906112, -16430034737688309104640, 4011640516519571786022912, -1097783068806961397511290880

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OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..100

FORMULA

a(n) = (2*n)! * [x^(2*n)] cosh(sin(x)^2).

MAPLE

a:= n-> coeff(series(cosh(sin(x)^2), x, 2*n+1), x, 2*n)*(2*n)!:

seq ( a(n), n=0..20); # Alois P. Heinz, Aug 15 2012

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Cosh[Sin[x]^2], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 15 2012 *)

CROSSREFS

Sequence in context: A119837 A012538 A006588 * A009080 A002166 A034910

Adjacent sequences: A009147 A009148 A009149 * A009151 A009152 A009153

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

More terms from, and definition clarified by, Harvey P. Dale, Aug 15 2012

STATUS

approved