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A013166 Expansion of e.g.f.: sech(arctanh(x)+log(x+1))=1-4/2!*x^2+6/3!*x^3+45/4!*x^4-300/5!*x^5... 0
1, 0, -4, 6, 45, -300, -630, 18270, -44415, -1428840, 13608000, 106964550, -3044747475, 2748645900, 674525001150, -6848689097250, -138141621993375, 3761985048822000, 12387014410270500, -1765001060909336250 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

MATHEMATICA

With[{nn=20}, CoefficientList[Series[Sech[ArcTanh[x]+Log[x+1]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jan 10 2019 *)

CROSSREFS

Sequence in context: A284634 A077100 A012935 * A174653 A274215 A119944

Adjacent sequences:  A013163 A013164 A013165 * A013167 A013168 A013169

KEYWORD

sign

AUTHOR

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

EXTENSIONS

Definition clarified by Harvey P. Dale, Jan 10 2019

STATUS

approved

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Last modified September 25 12:12 EDT 2022. Contains 356984 sequences. (Running on oeis4.)