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A009272 E.g.f. exp(tanh(x)*tan(x)), even powers only. 1
1, 2, 12, 232, 7952, 405152, 31111872, 3115956352, 414147567872, 68413355397632, 13936708915940352, 3412444856961083392, 987956358173680013312, 334650367409781717573632, 130572314003924554412900352, 58337032599905770133366013952 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..15.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Exp[Tanh[x]Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Feb 26 2012 *)

CROSSREFS

Sequence in context: A101712 A156484 A333447 * A013141 A013143 A009359

Adjacent sequences:  A009269 A009270 A009271 * A009273 A009274 A009275

KEYWORD

nonn

AUTHOR

R. H. Hardin

EXTENSIONS

Extended and signs tested Mar 15 1997 by Olivier Gérard.

More terms from Harvey P. Dale, Feb 26 2012

STATUS

approved

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Last modified July 24 23:25 EDT 2021. Contains 346273 sequences. (Running on oeis4.)