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A135388
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Number of (directed) Eulerian circuits on the complete graph K_{2n+1}.
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11
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2, 264, 129976320, 911520057021235200, 257326999238092967427785160130560, 6705710151431658873046319662156165939200000000000000, 32132958735643556926111996291480203406145819659840760945049600000000000000000
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OFFSET
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1,1
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REFERENCES
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B. D. McKay, Applications of a technique for labeled enumeration, Congress. Numerantium, 40 (1983), 207-221.
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LINKS
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FORMULA
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a(n) = A007082(n) * (n-1)!^(2*n+1).
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MATHEMATICA
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Table[2 Length[FindEulerianCycle[CompleteGraph[2 n + 1], All]], {n, 3}] (* Eric W. Weisstein, Jan 09 2018 *)
(* a(3) requires a very large amount of memory *)
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CROSSREFS
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KEYWORD
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nonn,walk
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AUTHOR
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STATUS
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approved
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