A013149 cosh(tanh(x)+arctan(x))=1+4/2!*x^2-16/4!*x^4+64/6!*x^6+4096/8!*x^8...

1, 4, -16, 64, 4096, -480896, 54717440, -7775895552, 1454255472640, -360442602684416, 116460747215831040, -47685470462142971904, 24020257118743960748032, -14514884376044102613991424

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cosh[Tanh[x]+ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Dec 13 2021 *)

Crossrefs

Sequence in context: A005401 A002923 A345365 * A175065 A373280 A033140

Adjacent sequences: A013146 A013147 A013148 * A013150 A013151 A013152

Keyword

sign

Author

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

Status

approved