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Search: id:A005014
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| A005014 |
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Certain subgraphs of a directed graph (inverse binomial transform of A005321).
(Formerly M4454)
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+0
1
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| 1, 1, 7, 97, 2911, 180481, 22740607, 5776114177, 2945818230271, 3010626231336961, 6159741269315422207, 25217980756577338515457, 206535262396368402441592831, 3383460668577307168798173757441
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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Andresen, E.; Kjeldsen, K.; On certain subgraphs of a complete transitively directed graph. Discrete Math. 14 (1976), no. 2, 103-119.
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LINKS
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N. J. A. Sloane, Transforms
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FORMULA
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a(n)=(-1)^n+[p(n)+p(n-1)]sum((-1)^j/p(j), j=0..n-1), where p(0)=1, p(k)=product(2^i-1, i=1..k) for k>0. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 23 2005
a(n) = (2^n-2)*a(n-1)-(-1)^n. - Vladeta Jovovic (vladeta(AT)Eunet.yu), Aug 20 2006
G.f.: Sum(x^n*Product((2^i-1)/(1+2^i*x),i=1..n),n=0..infinity). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Mar 10 2008
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MAPLE
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p:=proc(n) if n=0 then 1 else product(2^i-1, i=1..n) fi end: a:=n->(-1)^n+(p(n)+p(n-1))*sum((-1)^j/p(j), j=0..n-1): seq(a(n), n=1..14); (Deutsch)
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CROSSREFS
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Pairwise sums of A005327.
Adjacent sequences: A005011 A005012 A005013 this_sequence A005015 A005016 A005017
Sequence in context: A003710 A027837 A046908 this_sequence A022008 A124092 A036293
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KEYWORD
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nonn
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AUTHOR
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njas
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Aug 20 2006
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