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Search: id:A136246
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| A136246 |
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a(n) = (1/n!)*Sum_{k=0..n} (-1)^(n-k)*Stirling1(n,k)*A104179(k). |
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+0
1
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| 1, 1, 32, 2712, 449102, 122886128, 50225389432, 28670796914144, 21789885975738524, 21271115441652577064, 25938193213744579451420, 38638907727108476424404864, 69044758685363149615280762608
(list; graph; listen)
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OFFSET
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0,3
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FORMULA
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a(n) = Sum_{m>=0} binomial(binomial(m,3)+n-1,n)/2^(m+1).
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MAPLE
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A000629 := proc(n) local k ; sum( k^n/2^k, k=0..infinity) ; end: A104179 := proc(n) option remember ; local a, stir, ni, n1, n2, n3, stir2, i, j, tmp ; a := 0 ; if n = 0 then RETURN(1) ; fi ; stir := combinat[partition](n) ; stir2 := {} ; for i in stir do if nops(i) <= 3 then tmp := i ; while nops(tmp) < 3 do tmp := [op(tmp), 0] ; od: tmp := combinat[permute](tmp) ; for j in tmp do stir2 := stir2 union { j } ; od: fi ; od: for ni in stir2 do n1 := op(1, ni) ; n2 := op(2, ni) ; n3 := op(3, ni) ; a := a+combinat[multinomial](n, n1, n2, n3)*(A000629(3*n1+2*n2+n3)-1/2-2^(3*n1+2*n2+n3)/4)*(-3)^n2*2^n3 ; od: a/(2*6^n) ; end: A136246 := proc(n) local k ; add((-1)^(n-k)*combinat[stirling1](n, k)*A104179(k), k=0..n)/n! ; end: seq(A136246(n), n=0..14) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 01 2008
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CROSSREFS
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Cf. A121316.
Adjacent sequences: A136243 A136244 A136245 this_sequence A136247 A136248 A136249
Sequence in context: A101441 A077143 A111923 this_sequence A113500 A064018 A067321
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KEYWORD
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easy,nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)Eunet.yu), Mar 16 2008
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 01 2008
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