A013418 - OEIS

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A013418

tan(arcsin(x)-arcsinh(x)) = 2/3!*x^3+450/7!*x^7+4480/9!*x^9...

0, 2, 0, 450, 4480, 1786050, 61776000, 37240453250, 2713505184000, 2464296285701250, 308006231110240000, 397784819452992221250, 76036685958833418000000, 132964856302641623934781250

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

FORMULA

a(n) = (2n+1)! * [x^(2n+1)] tan(arcsin(x)-arcsinh(x)).

MAPLE

a:= n-> (2*n+1)!*coeff(series(tan(arcsin(x)-arcsinh(x)),

x, 2*n+2), x, 2*n+1):

seq(a(n), n=0..20); # Alois P. Heinz, Jul 20 2013

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tan[ArcSin[x]-ArcSinh[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Jul 20 2013 *)

CROSSREFS

Sequence in context: A012452 A339269 A013417 * A259435 A114630 A114632

Adjacent sequences: A013415 A013416 A013417 * A013419 A013420 A013421

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

a(0)=0 prepended and programs adapted by Vaclav Kotesovec, Feb 06 2015

STATUS

approved