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A290344 Denominators of the Kirchhoff (and Harary) index for the n-hypercube graph. 1
1, 1, 1, 3, 3, 15, 15, 105, 105, 315, 63, 693, 693, 9009, 9009, 45045, 45045, 765765, 765765, 14549535, 14549535, 14549535, 14549535, 334639305, 334639305, 1673196525, 1673196525, 5019589575, 5019589575, 145568097675, 145568097675, 4512611027925, 4512611027925 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..32.

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, 32}] // Denominator

Table[2^(-1 + n) n HypergeometricPFQ[{1, 1, 1 - n}, {2, 2}, -1], {n, 0, 32}] // Denominator (* Eric W. Weisstein, Dec 11 2017 *)

CROSSREFS

Cf. A290343 (numerators).

Sequence in context: A086116 A100735 A129356 * A217858 A185275 A055634

Adjacent sequences:  A290341 A290342 A290343 * A290345 A290346 A290347

KEYWORD

nonn,frac

AUTHOR

Eric W. Weisstein, Jul 28 2017

STATUS

approved

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Last modified May 18 10:19 EDT 2021. Contains 343995 sequences. (Running on oeis4.)