

A133068


Number of surjections from an nelement set to an eightelement set.


0



40320, 1451520, 30240000, 479001600, 6411968640, 76592355840, 843184742400, 8734434508800, 86355926616960, 823172919528960, 7621934141203200, 68937160460313600, 611692004959217280, 5342844138794426880
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OFFSET

8,1


LINKS

Table of n, a(n) for n=8..21.
Index to sequences with linear recurrences with constant coefficients, signature (36,546,4536,22449,67284,118124,109584,40320).


FORMULA

a(n)=sum((1)^(8k)*C(8,k)*k^n) with n>=8 and k=8,7,...,1.
a(n) = A049434(n) * 8! [From Max Alekseyev, Nov 13 2009]
G.f.: 40320*x^8/((x1)*(2*x1)*(3*x1)*(4*x1)*(5*x1)*(6*x1)*(7*x1)*(8*x1)). [Colin Barker, Oct 25 2012]


CROSSREFS

Cf. A000918, A000919, A000920, A001117, A001118, A135456.
Sequence in context: A179734 A061123 A029576 * A228911 A213878 A179063
Adjacent sequences: A133065 A133066 A133067 * A133069 A133070 A133071


KEYWORD

nonn,easy


AUTHOR

Mohamed Bouhamida (bhmd95(AT)yahoo.fr), Dec 16, 2007; Dec 21, 2007


EXTENSIONS

Edited by N. J. A. Sloane, Jul 12 2008 at the suggestion of R. J. Mathar
More terms from Max Alekseyev, Nov 13 2009


STATUS

approved



