A009653 Expansion of tan(log(1+x)/cosh(x)).

0, 1, -1, 1, -12, 55, -255, 2679, -23632, 201245, -2409525, 30433181, -383307804, 5609915779, -89478694851, 1470425213763, -26173709472960, 501554172182201, -10043883092049993, 212501921779526329, -4764376768067195020

Offset

0,5

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Mathematica

With[{nn=20}, CoefficientList[Series[Tan[Log[1+x]/Cosh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, May 28 2013 *)

Crossrefs

Sequence in context: A207102 A343539 A229424 * A133001 A340517 A104188

Adjacent sequences: A009650 A009651 A009652 * A009654 A009655 A009656

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, May 28 2013

Status

approved