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Search: id:A095664
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| 3, 25, 117, 405, 1155, 2871, 6435, 13299, 25740, 47190, 82654, 139230, 226746, 358530, 552330, 831402, 1225785, 1773783, 2523675, 3535675, 4884165, 6660225, 8974485, 11960325, 15777450, 20615868, 26700300, 34295052, 43709380, 55303380
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OFFSET
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0,1
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COMMENT
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If Y is a 3-subset of an n-set X then, for n>=10, a(n-10) is the number of 8-subsets of X having at most one element in common with Y. - Milan R. Janjic (agnus(AT)blic.net), Nov 23 2007
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FORMULA
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a(n)= binomial(n+7, 7)*(n+24)/8 = 3*b(n)-2*b(n-1), with b(n):=binomial(n+8, 8); cf. A000581.
G.f.: (3-2*x)/(1-x)^9.
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CROSSREFS
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Eighth column: A095663. Tenth column: A095665.
Adjacent sequences: A095661 A095662 A095663 this_sequence A095665 A095666 A095667
Sequence in context: A124245 A059457 A165206 this_sequence A099868 A112495 A034578
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KEYWORD
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nonn,easy
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AUTHOR
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Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Jun 11 2004
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