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A371174
Expansion of e.g.f. (1 + x + x^2)^(x^3).
0
1, 0, 0, 0, 24, 60, -480, 1260, 28224, 60480, -1447200, 1663200, 235509120, -311351040, -21211968960, 149707958400, 3435207874560, -21912886195200, -528501218918400, 7454163372364800, 111537899565004800, -1987208467140556800, -16841797212293222400
OFFSET
0,5
FORMULA
a(n) = n! * Sum_{j=0..n} Sum_{k=0..floor(j/3)} binomial(j-2*k,n-j-k) * Stirling1(j-2*k,k)/(j-2*k)!.
PROG
(PARI) a(n) = n!*sum(j=0, n, sum(k=0, j\3, binomial(j-2*k, n-j-k)*stirling(j-2*k, k, 1)/(j-2*k)!));
CROSSREFS
Cf. A371158.
Sequence in context: A370995 A226883 A304547 * A045558 A352343 A022761
KEYWORD
sign
AUTHOR
Seiichi Manyama, Mar 14 2024
STATUS
approved