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A320763
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Number of ordered set partitions of [n] where the maximal block size equals seven.
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2
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1, 16, 288, 5280, 101640, 2068704, 44595408, 1017804216, 24559319070, 625388375040, 16772475939648, 472802783660064, 13981054231585584, 432866241024085440, 14006847775868101440, 472893544571144089536, 16631451859811919417144, 608402197372214335559040
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OFFSET
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7,2
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LINKS
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FORMULA
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E.g.f.: 1/(1-Sum_{i=1..7} x^i/i!) - 1/(1-Sum_{i=1..6} x^i/i!).
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MAPLE
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b:= proc(n, k) option remember; `if`(n=0, 1, add(
b(n-i, k)*binomial(n, i), i=1..min(n, k)))
end:
a:= n-> (k-> b(n, k) -b(n, k-1))(7):
seq(a(n), n=7..25);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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