A013051 - OEIS

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A013051

Expansion of e.g.f. tanh(sinh(x)+tan(x)) (odd powers only).

2, -13, 289, -13039, 1003825, -118036631, 19683093369, -4418337316175, 1284612873046753, -469616483548721575, 210832414586400163561, -114033567896612568885023, 73135588741410223752308241, -54879566868084569212176674615, 47633391630419948548873776142041

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

2*x-13/3!*x^3+289/5!*x^5-13039/7!*x^7...

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tanh[Sinh[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, May 11 2022 *)

PROG

(PARI) my(x='x + O('x^40), v=Vec(serlaplace(tanh(sinh(x)+tan(x))))); vector(#v\2, k, v[2*k-1]) \\ Michel Marcus, Jun 20 2020

CROSSREFS

Sequence in context: A326360 A123113 A126742 * A351022 A012955 A357342

Adjacent sequences: A013048 A013049 A013050 * A013052 A013053 A013054

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

EXTENSIONS

More terms from Michel Marcus, Jun 20 2020

STATUS

approved