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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;
text;
internal format)
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OFFSET
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1,4
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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.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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Table of n, a(n) for n=1..15.
N. J. A. Sloane, Transforms
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FORMULA
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For n>1, a(n) = (2^(n-1)-1)*a(n-1) + (-1)^(n-1).
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, Jan 23 2005
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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->p(n-1)*sum((-1)^j/p(j), j=0..n-1): seq(a(n), n=1..17); (Deutsch)
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CROSSREFS
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Cf. A002820.
Sequence in context: A095864 A219220 A006151 * A182263 A171910 A113266
Adjacent sequences: A005324 A005325 A005326 * A005328 A005329 A005330
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane.
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EXTENSIONS
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More terms from Max Alekseyev, Apr 27 2010
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STATUS
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approved
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