A009397 Expansion of log(1+tanh(x)*sinh(x)).

0, 2, -16, 422, -22216, 1971002, -265691116, 50700975782, -13016429899216, 4327444080299762, -1808838826865938516, 928500311849311382942, -574198882099583321361016, 421058394568919310756145322

Offset

0,2

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Log[1+Tanh[x]*Sinh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Sep 07 2025 *)

Crossrefs

Sequence in context: A283408 A343428 A282309 * A229023 A009700 A358784

Adjacent sequences: A009394 A009395 A009396 * A009398 A009399 A009400

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Previous Mathematica program replaced by Harvey P. Dale, Sep 07 2025

Status

approved