OFFSET
0,1
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..200
FORMULA
a(n) ~ 2 * (2*n+1)! / ((1/sqrt(1-r^2) + cosh(r)) * r^(2*n+2)), where r = 0.7137663392321306757068472447735817625797877657851167410885... is the root of the equation sinh(r) + arcsin(r) = Pi/2. - Vaclav Kotesovec, Feb 07 2015
MATHEMATICA
nn = 20; Table[(CoefficientList[Series[Tan[ArcSin[x] + Sinh[x]], {x, 0, 2*nn+1}], x] * Range[0, 2*nn+1]!)[[n]], {n, 2, 2*nn, 2}] (* Vaclav Kotesovec, Feb 07 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved