OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..379
FORMULA
a(n) ~ n!/(sqrt(10)*(log(1/3+sqrt(10)/3))^(n+1)). - Vaclav Kotesovec, Jun 26 2013
a(0) = 1; a(n) = 3 * Sum_{k=0..floor((n-1)/2)} binomial(n,2*k+1) * a(n-2*k-1). - Ilya Gutkovskiy, Mar 10 2022
MAPLE
E(x):=1/(1-3*sinh(x)): f[0]:=E(x): for n from 1 to 30 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n], n=0..30);
MATHEMATICA
CoefficientList[Series[1/(1-3*Sinh[x]), {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Jun 26 2013 *)
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(1-3*sinh(x)))) \\ Seiichi Manyama, Mar 26 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Miklos Kristof, Jun 09 2005
STATUS
approved