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A276927
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Number of ordered set partitions of [n] with at most seven elements per block.
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5
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1, 1, 3, 13, 75, 541, 4683, 47293, 545834, 7087242, 102247182, 1622624850, 28091404902, 526854753282, 10641259374174, 230281144233426, 5315601950221992, 130369339178641992, 3385494089758915992, 92800379366660198376, 2677650178353887869704
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OFFSET
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0,3
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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!).
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 1, add(
a(n-i)*binomial(n, i), i=1..min(n, 7)))
end:
seq(a(n), n=0..25);
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MATHEMATICA
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max = 25; CoefficientList[1/(1-Sum[x^i/i!, {i, 1, 7}]) + O[x]^(max+1), x]* Range[0, max]! (* Jean-François Alcover, May 24 2018 *)
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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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