A009342 Expansion of e.g.f.: log(1+sin(x)/cosh(x)).

0, 1, -1, -2, 10, -20, -16, 488, -4080, 22160, -7936, -1616672, 22996480, -172976960, -22368256, 25518205568, -485458114560, 4964227109120, -209865342976, -1231298393825792, 29816107240652800, -379260096755225600

Offset

0,4

Links

Table of n, a(n) for n=0..21.

Mathematica

With[{nn=30}, CoefficientList[Series[Log[1+Sin[x]/Cosh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, May 14 2026 *)

Crossrefs

Cf. A012816.

Sequence in context: A346810 A347024 A384644 * A357486 A350508 A306105

Adjacent sequences: A009339 A009340 A009341 * A009343 A009344 A009345

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and previous Mathematica program replaced by Harvey P. Dale, May 14 2026

Status

approved