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A013091 E.g.f.: exp(arcsinh(x)+tan(x)) = 1 + 2*x + 4/2!*x^2 + 9/3!*x^3 + 24/4!*x^4 + 97/5!*x^5 + .... 0
1, 2, 4, 9, 24, 97, 534, 2975, 16520, 114217, 1017914, 8693355, 66612612, 641356549, 8612481206, 99659748575, 839464647792, 10015783072433, 223263066398386, 3322983000373651, 20349154329810172 (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+sqrt(1+x^2))*exp(tan(x)). - Vaclav Kotesovec, Nov 01 2013

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

MATHEMATICA

With[{nn=30}, CoefficientList[Series[Exp[ArcSinh[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Sep 19 2012 *)

CROSSREFS

Sequence in context: A006406 A097656 A012936 * A013168 A013183 A049963

Adjacent sequences:  A013088 A013089 A013090 * A013092 A013093 A013094

KEYWORD

sign

AUTHOR

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

EXTENSIONS

Definition clarified by Harvey P. Dale, Sep 19 2012

STATUS

approved

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Last modified March 26 23:19 EDT 2017. Contains 284141 sequences.