A013183 - OEIS

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A013183

exp(arctanh(x)+arcsinh(x)) = 1+2*x+4/2!*x^2+9/3!*x^3+24/4!*x^4+105/5!*x^5...

1, 2, 4, 9, 24, 105, 630, 4095, 27720, 235305, 2353050, 24792075, 267567300, 3350672325, 46909412550, 682570263375, 10103827734000, 167108397080625, 3007951147451250, 55823919598321875, 1049953727680357500

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

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..20.

FORMULA

E.g.f.: ((x+1)/sqrt(1-x^2))*(x+sqrt(1+x^2)). - Vaclav Kotesovec, Oct 24 2013

a(n) ~ 2*(1+sqrt(2)) * n^n / exp(n). - Vaclav Kotesovec, Oct 24 2013

MATHEMATICA

CoefficientList[Series[Exp[ArcTanh[x]+ArcSinh[x]], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Oct 24 2013 *)

CROSSREFS

Sequence in context: A012936 A013091 A013168 * A049963 A368458 A114110

Adjacent sequences: A013180 A013181 A013182 * A013184 A013185 A013186

KEYWORD

nonn

AUTHOR

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

STATUS

approved