A012005 tanh(log(cos(x)))=-1/2!*x^2-2/4!*x^4+14/6!*x^6+568/8!*x^8...

-1, -2, 14, 568, 9704, -229712, -35581456, -1790014592, 72312646784, 28603722780928, 3039116082823424, -154149928667313152, -135793191600734657536, -25782484156469234296832

Offset

0,2

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[Log[Cos[x]]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 2}]] (* Harvey P. Dale, May 12 2022 *)

Crossrefs

Sequence in context: A005806 A015184 A012002 * A342181 A294353 A156172

Adjacent sequences: A012002 A012003 A012004 * A012006 A012007 A012008

Keyword

sign

Author

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

Status

approved