A012120 - OEIS

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A012120

cosh(arcsin(arcsinh(x)))=1+1/2!*x^2+1/4!*x^4+49/6!*x^6+1/8!*x^8...

1, 1, 1, 49, 1, 83361, -2206335, 961321425, -96313079295, 41773143339585, -9493597481579775, 4967941000109596785, -1991874953215606007295, 1319075774798596975837665, -807077677117010238256087935

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

LINKS

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

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Cosh[ArcSin[ArcSinh[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 22 2013 *)

CROSSREFS

Sequence in context: A174696 A203506 A254617 * A278107 A218167 A145583

Adjacent sequences: A012117 A012118 A012119 * A012121 A012122 A012123

KEYWORD

sign

AUTHOR

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

STATUS

approved