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A367885 Expansion of e.g.f. 1/(1 - x * (exp(2*x) - 1)). 1
1, 0, 4, 12, 128, 1040, 12672, 161728, 2481152, 41806080, 791613440, 16399944704, 371591995392, 9110211874816, 240670782291968, 6810264853463040, 205583847590985728, 6593508525460226048, 223913466256013918208, 8026367531323488993280 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
a(0) = 1; a(n) = n * Sum_{k=2..n} 2^(k-1) * binomial(n-1,k-1) * a(n-k).
a(n) = n! * Sum_{k=0..floor(n/2)} 2^(n-k) * k! * Stirling2(n-k,k)/(n-k)!.
PROG
(PARI) a(n) = n!*sum(k=0, n\2, 2^(n-k)*k!*stirling(n-k, k, 2)/(n-k)!);
CROSSREFS
Sequence in context: A249788 A032323 A331905 * A053551 A009663 A197899
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 04 2023
STATUS
approved

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Last modified February 29 08:54 EST 2024. Contains 370418 sequences. (Running on oeis4.)