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A005331
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Certain subgraphs of a directed graph (binomial transform of A005321).
(Formerly M1531)
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2
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1, 2, 5, 20, 179, 4082, 218225, 25316720, 6135834479, 3047003143022, 3067545380897645, 6223557209578656620, 25360384878802358268779, 207167485813280961035481962, 3389045635023473628621934703465, 110960673463328354866093662279119720, 7268699514166911556909103208203294815079
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listen;
history;
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internal format)
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OFFSET
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0,2
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REFERENCES
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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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FORMULA
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a(n) = Sum_{j=0..n} binomial(n,j)*A005321(j).
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MATHEMATICA
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Block[{nn = 16, s}, s = CoefficientList[Series[Sum[x^n*Product[(2^i - 1)/(1 + (2^i - 1)*x), {i, n}], {n, 0, #}], {x, 0, #}], x] &@ nn; Array[Sum[Binomial[#, j] s[[j + 1]], {j, 0, #}] &, nn + 1, 0]] (* Michael De Vlieger, Apr 13 2021, after Jean-François Alcover at A005321 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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