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%I #11 Dec 11 2017 17:45:59
%S 1,1,1,3,3,15,15,105,105,315,63,693,693,9009,9009,45045,45045,765765,
%T 765765,14549535,14549535,14549535,14549535,334639305,334639305,
%U 1673196525,1673196525,5019589575,5019589575,145568097675,145568097675,4512611027925,4512611027925
%N Denominators of the Kirchhoff (and Harary) index for the n-hypercube graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HararyIndex.html">Harary Index</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HypercubeGraph.html">Hypercube Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/KirchhoffIndex.html">Kirchhoff Index</a>
%e Kirchhoff (and Harary) indices are 0, 1, 5, 58/3, 206/3, 3548/15, 12136/15, 291824/105, 1012048/105, ....
%t Table[-2^(n - 1) HarmonicNumber[n] - 4^n Re[LerchPhi[2, 1, n + 1]], {n, 0, 32}] // Denominator
%t Table[2^(-1 + n) n HypergeometricPFQ[{1, 1, 1 - n}, {2, 2}, -1], {n, 0, 32}] // Denominator (* _Eric W. Weisstein_, Dec 11 2017 *)
%Y Cf. A290343 (numerators).
%K nonn,frac
%O 0,4
%A _Eric W. Weisstein_, Jul 28 2017
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