OFFSET
0,4
FORMULA
E.g.f.: B(x)^2, where B(x) is the e.g.f. of A375167.
a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k+1)! * |Stirling1(k,n-2*k)|/(2^k*k!).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+x*log(1-x^2/2))^2))
(PARI) a(n) = n!*sum(k=0, n\2, (n-2*k+1)!*abs(stirling(k, n-2*k, 1))/(2^k*k!));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 23 2024
STATUS
approved