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Search: id:A052875
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| 0, 0, 2, 12, 74, 540, 4682, 47292, 545834, 7087260, 102247562, 1622632572, 28091567594, 526858348380, 10641342970442, 230283190977852, 5315654681981354, 130370767029135900, 3385534663256845322
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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Stirling transform of A005359(n-1)=[0,0,2,0,24,0,...] is a(n-1)=[0,0,2,12,74,...]. - Michael Somos Mar 04 2004
Stirling transform of -(-1)^n*A052566(n-1)=[1,-1,4,-6,48,...] is a(n-1)=[1,0,2,12,74,...]. - Michael Somos Mar 04 2004
Stirling transform of A000142(n)=[0,2,6,24,120,...] is a(n)=[0,2,12,74,...]. - Michael Somos Mar 04 2004
Stirling transform of A007680(n)=[2,10,42,216,...] is a(n+1)=[2,12,74,...]. - Michael Somos Mar 04 2004
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LINKS
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INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 846
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FORMULA
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Second column of A084416: Sum_{i=2..n} i!*Stirling2(n, i) = A000670(n)-1. - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 15 2003
E.g.f.: (exp(x)-1)^2/(2-exp(x)).
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MAPLE
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spec := [S, {B=Set(Z, 1 <= card), C=Sequence(B, 1 <= card), S=Prod(B, C)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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PROGRAM
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(PARI) a(n)=if(n<0, 0, n!*polcoeff(subst(y^2/(1-y), y, exp(x+x*O(x^n))-1), n))
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CROSSREFS
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Sequence in context: A014351 A074616 A006936 this_sequence A037725 A037620 A121680
Adjacent sequences: A052872 A052873 A052874 this_sequence A052876 A052877 A052878
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KEYWORD
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easy,nonn
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AUTHOR
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encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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