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Search: id:A133068
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| A133068 |
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Number of surjections from an n-element set to an eight-element set. |
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+0
1
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| 40320, 1451520, 30240000, 479001600, 6411968640, 76592355840
(list; graph; listen)
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OFFSET
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8,1
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FORMULA
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a(n)=sum((-1)^(8-k)*C(8,k)*k^n) with n>=8 and k=8,7,...,1.
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CROSSREFS
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Cf. A000918, A000919, A000920, A001117, A001118, A135456.
Adjacent sequences: A133065 A133066 A133067 this_sequence A133069 A133070 A133071
Sequence in context: A090394 A061123 A029576 this_sequence A045516 A071550 A072269
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KEYWORD
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nonn
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AUTHOR
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Mohamed Bouhamida (bhmd95(AT)yahoo.fr), Dec 16, 2007; Dec 21, 2007
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EXTENSIONS
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Edited by njas, Jul 12 2008 at the suggestion of R. J. Mathar
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