OFFSET
0,5
FORMULA
a(n) = n! * Sum_{k=1..floor(n/4)} (k-1)! * Stirling2(n-3*k,k)/(n-3*k)!.
MATHEMATICA
With[{nn=30}, CoefficientList[Series[-Log[1-x^3 (Exp[x]-1)], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Mar 22 2026 *)
PROG
(PARI) a(n) = n!*sum(k=1, n\4, (k-1)!*stirling(n-3*k, k, 2)/(n-3*k)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 15 2023
STATUS
approved
