OFFSET
0,4
FORMULA
E.g.f.: Sum_{k>=0} x^k / (k! * (1 - (k*x)^2)).
PROG
(PARI) a(n) = n!*sum(k=0, n\2, (n-2*k)^(2*k)/(n-2*k)!);
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, x^k/(k!*(1-(k*x)^2)))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 15 2022
STATUS
approved