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Search: id:A096946
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| 5, 41, 189, 645, 1815, 4455, 9867, 20163, 38610, 70070, 121550, 202878, 327522, 513570, 784890, 1172490, 1716099, 2465991, 3485075, 4851275, 6660225, 9028305, 12096045, 16031925, 21036600, 27347580, 35244396, 45054284, 57158420
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OFFSET
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0,1
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COMMENT
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If Y is a 5-subset of an n-set X then, for n>=12, a(n-12) is the number of 8-subsets of X having at most one element in common with Y. > - Milan R. Janjic (agnus(AT)blic.net), Dec 08 2007
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FORMULA
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a(n)= (n+40)*binomial(n+7, 7)/8 = 5*b(n)-4*b(n-1), with b(n):=A000581(n+8)=binomial(n+8, 8).
G.f.: (5-4*x)/(1-x)^9.
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CROSSREFS
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Eighth column: A096945; tenth column: A096947.
Sequence in context: A056905 A088547 A105412 this_sequence A027954 A083300 A067381
Adjacent sequences: A096943 A096944 A096945 this_sequence A096947 A096948 A096949
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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), Jul 16 2004
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