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A024282
Expansion of e.g.f. tanh(x)*sin(sin(x))/2, even powers only.
2
0, 1, -8, 124, -3168, 121232, -6609664, 491033408, -47878820864, 5942382135552, -915386669357056, 171409533142952960, -38347910567533715456, 10102227232688591245312, -3095277524018668920373248
OFFSET
0,3
LINKS
FORMULA
a(n) ~ (-1)^(n+1) * sinh(sinh(Pi/2)) * 2^(2*n+1) * (2*n)! / Pi^(2*n+1). - Vaclav Kotesovec, Apr 20 2014
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tanh[x]Sin[Sin[x]]/2, {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Oct 20 2013 *)
PROG
(PARI) A024282=n->{my(t=x+O(x^(2*n+!n))); polcoeff(tanh(t)*sin(sin(t)), n*2, x)/2*(2*n)!} \\ M. F. Hasler, Feb 09 2014
CROSSREFS
Cf. A009833.
Sequence in context: A069459 A254125 A371298 * A340888 A231638 A065082
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Prior Mathematica program replaced by Harvey P. Dale, Oct 20 2013
Clarified definition, Joerg Arndt, Feb 09 2014
STATUS
approved