

A076301


Related to number of labeled partially ordered sets.


1



1, 1, 3, 15, 96, 720, 6120, 57960, 604800, 6894720, 85276800, 1137628800, 16286054400, 249080832000, 4053790540800, 69960578688000, 1276290183168000, 24542432538624000, 496183962193920000, 10522301185363968000
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OFFSET

0,3


LINKS

G. C. Greubel, Table of n, a(n) for n = 0..445
M. Janjic and B. Petkovic, A Counting Function, arXiv 1301.4550 [math.CO], 2013


FORMULA

E.g.f. (24*x+3*x^2)/(6*x^22+6*x+2*x^3).
a(n) = (4 n +n^2)*n!/4.  G. C. Greubel, May 04 2018


MAPLE

seq(1/4*(4n+n^2)*n!, n=0..30);


MATHEMATICA

Table[(4 n +n^2)*n!/4, {n, 0, 30}] (* G. C. Greubel, May 04 2018 *)


PROG

(PARI) for(n=0, 30, print1((4 n +n^2)*n!/4, ", ")) \\ G. C. Greubel, May 04 2018
(MAGMA) [(4 n +n^2)*Factorial(n)/4: n in [0..30]]; // G. C. Greubel, May 04 2018


CROSSREFS

Sequence in context: A220262 A306027 A304072 * A112913 A109283 A079689
Adjacent sequences: A076298 A076299 A076300 * A076302 A076303 A076304


KEYWORD

nonn


AUTHOR

Detlef Pauly (dettodet(AT)yahoo.de), Mar 14 2003


STATUS

approved



