OFFSET
1,3
FORMULA
a(n) ~ (2*n-1)! * (-1)^(n+1) * 8 / ((4 + Pi^2) * (log((Pi + sqrt(4 + Pi^2))/2))^(2*n)). - Vaclav Kotesovec, Jan 24 2015
MATHEMATICA
Tanh[ Sin[ x ] ]/Cos[ x ] (* Odd Part *)
nn = 20; Table[(CoefficientList[Series[Sec[x]*Tanh[Sin[x]], {x, 0, 2*nn+1}], x] * Range[0, 2*nn+1]!)[[n]], {n, 2, 2*nn, 2}] (* Vaclav Kotesovec, Jan 24 2015 *)
CROSSREFS
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Changed offset by Vaclav Kotesovec, Jan 24 2015
STATUS
approved