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A013096 cos(arcsinh(x)+tan(x))=1-4/2!*x^2+8/4!*x^4-214/6!*x^6+8632/8!*x^8... 0
1, -4, 8, -214, 8632, -381754, 56522540, -6087452310, 1458087413200, -333863833250482, 114840891055289940, -44663949601714088046, 21870152705694370672888, -12543311598815172475041226 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

FORMULA

a(n) ~ (-1)^n * 2^(2*n) * n^(2*n-1) * sinh(Pi/2+tanh(1)) / exp(2*n). - Vaclav Kotesovec, Nov 01 2013

MATHEMATICA

Table[n!*SeriesCoefficient[Cos[ArcSinh[x]+Tan[x]], {x, 0, n}], {n, 0, 40, 2}] (* Vaclav Kotesovec, Nov 01 2013 *)

With[{nn=30}, Take[CoefficientList[Series[Cos[ArcSinh[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 18 2017 *)

CROSSREFS

Sequence in context: A133262 A120822 A013065 * A200729 A116092 A085631

Adjacent sequences: A013093 A013094 A013095 * A013097 A013098 A013099

KEYWORD

sign

AUTHOR

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

STATUS

approved

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Last modified January 30 22:45 EST 2023. Contains 359947 sequences. (Running on oeis4.)