A013406 - OEIS

A013406

sech(arcsin(x)-tan(x))=1-10/6!*x^6-392/8!*x^8-11814/10!*x^10...

1, 0, 0, -10, -392, -11814, 496012, 255399014, 69358453968, 19258160456306, 6077931425640244, 2258231645186973342, 999755491596900217336, 527324363004530542073450, 328862882324660659119175452

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OFFSET

0,4

LINKS

Table of n, a(n) for n=0..14.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Sech[ArcSin[x]-Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 30 2021 *)

CROSSREFS

Sequence in context: A013405 A013404 A013402 * A183487 A172505 A098722

Adjacent sequences: A013403 A013404 A013405 * A013407 A013408 A013409

KEYWORD

sign

AUTHOR

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

STATUS

approved