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A377393
Expansion of e.g.f. (1/x) * Series_Reversion( x/(1 + x*(exp(x) - 1))^3 ).
1
1, 0, 6, 9, 516, 3075, 149418, 1956171, 95139432, 2099836899, 108189172830, 3465051871083, 194015893087404, 8207832658120563, 505114926236953074, 26525536061251639275, 1800555184934893332048, 112493970299385975997635, 8415880480577316204054630
OFFSET
0,3
FORMULA
E.g.f. satisfies A(x) = ( 1 + x*A(x) * (exp(x*A(x)) - 1) )^3.
E.g.f.: B(x)^3, where B(x) is the e.g.f. of A371272.
a(n) = 3 * n! * (3*n+2)! * Sum_{k=0..floor(n/2)} Stirling2(n-k,k)/( (n-k)! * (3*n-k+3)! ).
PROG
(PARI) a(n) = 3*n!*(3*n+2)!*sum(k=0, n\2, stirling(n-k, k, 2)/((n-k)!*(3*n-k+3)!));
CROSSREFS
Cf. A371272.
Sequence in context: A377691 A377686 A264375 * A377391 A376382 A376386
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 27 2024
STATUS
approved