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A054954
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Number of unlabeled semi-strong digraphs on n nodes with an even number of pairwise different components.
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4
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0, 0, 1, 5, 88, 5141, 1052471, 706498013, 1581059448184, 12140608800384871, 328173098339746387013, 31831409094194340869533850, 11234306830091593156638822493531, 14576263867574000953696306880725802283
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OFFSET
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1,4
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LINKS
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FORMULA
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MATHEMATICA
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m = 15;
A035512 = Cases[Import["https://oeis.org/A035512/b035512.txt", "Table"], {_, _}][[All, 2]];
gf = -2 + Product[(1 - x^n)^A035512[[n + 1]], {n, 1, m}] + Product[(1 + x^n)^A035512[[n + 1]], {n, 1, m}];
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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