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A013100 cosh(arcsinh(x)+tan(x))=1+4/2!*x^2+24/4!*x^4+534/6!*x^6+16520/8!*x^8... 0
1, 4, 24, 534, 16520, 1017914, 66612612, 8612481206, 839464647792, 223263066398386, 20349154329810172, 15355587487339427086, -408311328299061735320, 2681720930486026740373066, -832148640269649203971185996, 1101363338244005265784426750566 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..15.

FORMULA

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

MATHEMATICA

With[{nn=40}, Take[CoefficientList[Series[Cosh[ArcSinh[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Feb 23 2013 *)

CROSSREFS

Sequence in context: A009535 A139096 A111425 * A013061 A071302 A211215

Adjacent sequences:  A013097 A013098 A013099 * A013101 A013102 A013103

KEYWORD

sign

AUTHOR

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

EXTENSIONS

Checked by N. J. A. Sloane, Dec 17 2011

More terms from Harvey P. Dale, Feb 23 2013

STATUS

approved

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Last modified August 17 21:11 EDT 2017. Contains 290656 sequences.