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A005327
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Certain subgraphs of a directed graph (inverse binomial transform of A005321).
(Formerly M4289)
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3
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1, 0, 1, 6, 91, 2820, 177661, 22562946, 5753551231, 2940064679040, 3007686166657921, 6156733583148764286, 25211824022994189751171, 206510050572345408251841660, 3383254158526734823389921915781
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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REFERENCES
| Andresen, E.; Kjeldsen, K.; On certain subgraphs of a complete transitively directed graph. Discrete Math. 14 (1976), no. 2, 103-119.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
| N. J. A. Sloane, Transforms
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FORMULA
| a(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
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MAPLE
| p:=proc(n) if n=0 then 1 else product(2^i-1, i=1..n) fi end: a:=n->p(n-1)*sum((-1)^j/p(j), j=0..n-1): seq(a(n), n=1..17); (Deutsch)
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CROSSREFS
| Cf. A002820.
Sequence in context: A077370 A095864 A006151 * A171910 A113266 A053512
Adjacent sequences: A005324 A005325 A005326 * A005328 A005329 A005330
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Max Alekseyev (maxale(AT)gmail.com), Apr 27 2010
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