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A270498
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Sum of the sizes of the sixth blocks in all set partitions of {1,2,...,n}.
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2
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1, 23, 324, 3645, 36223, 334751, 2965654, 25691104, 220643295, 1897548384, 16463907354, 144927422746, 1299763249771, 11912250951457, 111803042249042, 1076045623549383, 10628068291940557, 107760039986995689, 1121581530251066296, 11980190581723881858
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OFFSET
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6,2
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LINKS
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MAPLE
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b:= proc(n, m) option remember; `if`(n=0, [1, 0],
add((p->`if`(j<7, [p[1], p[2]+p[1]*x^j], p))(
b(n-1, max(m, j))), j=1..m+1))
end:
a:= n-> coeff(b(n, 0)[2], x, 6):
seq(a(n), n=6..30);
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MATHEMATICA
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b[n_, m_] := b[n, m] = If[n == 0, {1, 0}, Sum[Function[p, If[j < 7, {p[[1]], p[[2]] + p[[1]]*x^j}, p]][b[n - 1, Max[m, j]]], {j, 1, m + 1}]];
a[n_] := Coefficient[b[n, 0][[2]], x, 6];
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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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