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A009150
Expansion of e.g.f. cosh(sin(x)^2) (even coefficients).
1
1, 0, 12, -240, 5712, -266880, 18566592, -1488963840, 141287377152, -16736203345920, 2412897423240192, -402658140395089920, 76287123858146906112, -16430034737688309104640, 4011640516519571786022912, -1097783068806961397511290880
OFFSET
0,3
LINKS
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
KEYWORD
sign
AUTHOR
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