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A013281

Expansion of e.g.f.: sech(log(x+1)-arcsinh(x))=1-3/4!*x^4+30/5!*x^5-180/6!*x^6+945/7!*x^7...

1, 0, 0, 0, -3, 30, -180, 945, -6615, 56700, -368550, 1091475, 3274425, -85135050, 3235131900, -86199238125, 1340238524625, -15196606425000, 229968074085750, -4642248475990125, 57810007510880625

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OFFSET

0,5

LINKS

Table of n, a(n) for n=0..20.

MATHEMATICA

With[{nn=20}, CoefficientList[Series[Sech[Log[x+1]-ArcSinh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Dec 05 2025 *)

CROSSREFS

Sequence in context: A002463 A360645 A344564 * A013274 A013279 A013280

Adjacent sequences: A013278 A013279 A013280 * A013282 A013283 A013284

KEYWORD

sign

AUTHOR

Patrick Demichel

EXTENSIONS

Definition clarified by Harvey P. Dale, Dec 05 2025

STATUS

approved

URL: https://oeis.org/A013281

⇱ A013281 - OEIS