OFFSET
0,4
FORMULA
a(0) = 1; a(n) = Sum_{k=0..floor((n-3)/2)} (2*k+2)! * binomial(n,2*k+3) * a(n-2*k-3).
E.g.f.: 1 / ( 1 + x - arctanh(x) ).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+x-atanh(x))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 23 2023
STATUS
approved