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A290343
Numerators of the Kirchhoff (and Harary) index for the n-hypercube graph.
1
0, 1, 5, 58, 206, 3548, 12136, 291824, 1012048, 10650848, 7560128, 298378880, 1081081600, 51358504448, 189080845312, 3502982600704, 13051710507008, 830688808865792, 3123121211121664, 223924345487409152, 847782882348335104
OFFSET
0,3
LINKS
Eric Weisstein's World of Mathematics, Harary Index
Eric Weisstein's World of Mathematics, Hypercube Graph
Eric Weisstein's World of Mathematics, Kirchhoff Index
EXAMPLE
Kirchhoff (and Harary) indices are 0, 1, 5, 58/3, 206/3, 3548/15, 12136/15, 291824/105, 1012048/105, ....
MATHEMATICA
Table[-2^(n - 1) HarmonicNumber[n] - 4^n Re[LerchPhi[2, 1, n + 1]], {n, 0, 20}] // Numerator
Table[2^(-1 + n) n HypergeometricPFQ[{1, 1, 1 - n}, {2, 2}, -1], {n, 0, 20}] // Numerator (* Eric W. Weisstein, Dec 11 2017 *)
CROSSREFS
Cf. A290344 (denominators).
Sequence in context: A086060 A068003 A295902 * A173202 A104099 A334698
KEYWORD
nonn,frac
AUTHOR
Eric W. Weisstein, Jul 28 2017
STATUS
approved