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A012558 arctan(sinh(x)*arctan(x))=2/2!*x^2-4/4!*x^4-130/6!*x^6+2200/8!*x^8... 0
0, 2, -4, -130, 2200, 393178, -36230060, -2241493098, 696842413488, 151155071419698, -94998751466350804, 4870009119362109230, 9231493784347343489864, 1174397467642045406094346 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[ArcTan[Sinh[x]*ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Ray Chandler, Nov 28 2016 *)

CROSSREFS

Sequence in context: A009073 A326213 A012561 * A012617 A012614 A018500

Adjacent sequences: A012555 A012556 A012557 * A012559 A012560 A012561

KEYWORD

sign

AUTHOR

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

STATUS

approved

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Last modified February 6 10:18 EST 2023. Contains 360104 sequences. (Running on oeis4.)