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A009683
Expansion of tan(sinh(x))*x.
1
0, 2, 12, 222, 8120, 478810, 41517828, 4965965942, 783389808112, 157572900435762, 39359784790117500, 11953192658425797262, 4337232551752795660968, 1853172813592086586350218
OFFSET
0,2
FORMULA
a(n) ~ (2*n)! * 4 / (sqrt(4+Pi^2) * log((Pi + sqrt(4+Pi^2))/2)^(2*n)). - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
Tan[ Sinh[ x ] ]*x (* Even Part *)
nn = 20; Table[(CoefficientList[Series[x*Tan[Sinh[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Jan 23 2015 *)
CROSSREFS
Sequence in context: A374871 A092124 A009525 * A132879 A348332 A101712
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested Mar 15 1997 by Olivier Gérard.
STATUS
approved