OFFSET
0,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..100
PROG
(PARI) \\ here b(n) is A000522.
b(n)={sum(k=0, n, binomial(n, k)*k!)}
a(n)={(b(4*n) + 6*b(2*n) + 8*b(n) + 9) / 24} \\ Andrew Howroyd, Jan 27 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Aug 22 2003
EXTENSIONS
Terms a(9) and beyond from Andrew Howroyd, Jan 27 2020
STATUS
approved