A012721 - OEIS

A012721

exp(arctanh(x)*sin(x))=1+2/2!*x^2+16/4!*x^4+350/6!*x^6+16280/8!*x^8...

1, 2, 16, 350, 16280, 1280458, 151282316, 25067231982, 5547679327632, 1580745016902930, 563647979697490836, 245869122688036168950, 128799713392548410995032, 79791827954988156443060506

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

OFFSET

0,2

LINKS

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

EXAMPLE

a(n) ~ 2 * (2*n-1)! * (4*n)^(sin(1)/2) / GAMMA(sin(1)/2). - Vaclav Kotesovec, Oct 24 2013

MATHEMATICA

Table[n!*SeriesCoefficient[Exp[ArcTanh[x]*Sin[x]], {x, 0, n}], {n, 0, 40, 2}] (* Vaclav Kotesovec, Oct 24 2013 *)

CROSSREFS

Sequence in context: A275854 A299907 A012610 * A297095 A289972 A179472

Adjacent sequences: A012718 A012719 A012720 * A012722 A012723 A012724

KEYWORD

nonn

AUTHOR

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

STATUS

approved