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A029706
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Sum C(n,k)*b(k), k=1..n, where b(k) is given by A001861.
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1
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2, 10, 46, 226, 1214, 7106, 44958, 305090, 2206398, 16913986, 136823262, 1163490498, 10366252030, 96491364674, 935976996126, 9440144423874, 98800604237118, 1071092025420866, 12008090971866206, 139014305916844738
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OFFSET
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0,1
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LINKS
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FORMULA
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MATHEMATICA
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a[n_] := Sum[Binomial[n, k]*BellB[k, 2], {k, 1, n}]; Table[a[n], {n, 1, 20}] (* Jean-François Alcover, Apr 26 2013 *)
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PROG
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(PARI) x='x+O('x^66); Vec(serlaplace(1/2-exp(x)+1/2*exp(2*exp(x)-2))) \\ Joerg Arndt, Apr 21 2013
(PARI) a(n) = sum(k=1, n, binomial(n, k)*sum(j=1, k, stirling(k, j, 2)*2^j)); \\ \\ Michel Marcus, Apr 26 2013
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CROSSREFS
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Arises if one of the two kinds of boxes mentioned in A001861 may 'fail'.
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KEYWORD
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nonn
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AUTHOR
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Andre Poenitz (andre.poenitz(AT)mathematik.tu-chemnitz.de)
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EXTENSIONS
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STATUS
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approved
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