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A192826 Molecular topological indices of the folded cube graphs. 4
4, 72, 448, 2400, 13824, 72128, 389120, 1949184, 9932800, 47950848, 234160128, 1098559488, 5200642048, 23876812800, 110456995840, 498763431936, 2266990903296, 10103408033792, 45289255731200, 199725155352576, 885321097019392 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Andrew Howroyd, Table of n, a(n) for n = 2..200

Eric Weisstein's World of Mathematics, Folded Cube Graph

Eric Weisstein's World of Mathematics, Molecular Topological Index

FORMULA

a(n) = 2^(n-2)*n^2*(2 + 2^(n-1) - binomial(n-1,floor((n-1)/2))), for n>2. - Andrew Howroyd, May 11 2017

MATHEMATICA

a[2] = 4; a[n_] := 2^(n-2)*n^2*(2 + 2^(n-1) - Binomial[n-1, Floor @ ((n-1)/2)]); Array[a, 21, 2] (* Jean-Fran├žois Alcover, Nov 01 2017, after Andrew Howroyd *)

PROG

(PARI) {a(n) = if(n==2, 4, 2^(n-2)*n^2*(2 +2^(n-1) -binomial(n-1, floor((n-1)/2))))}; \\ G. C. Greubel, Jan 03 2019

(MAGMA) [4] cat [2^(n-2)*n^2*(2 +2^(n-1) -Binomial(n-1, Floor((n-1)/2))): n in [3..30]] // G. C. Greubel, Jan 03 2019

(Sage) [4] + [2^(n-2)*n^2*(2 +2^(n-1) -binomial(n-1, floor((n-1)/2))) for n in (3..30)] # G. C. Greubel, Jan 03 2019

CROSSREFS

Cf. A192831, A192830.

Sequence in context: A203537 A095385 A071683 * A190398 A003752 A062018

Adjacent sequences:  A192823 A192824 A192825 * A192827 A192828 A192829

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, Jul 10 2011

EXTENSIONS

a(11)-a(22) from Andrew Howroyd, May 11 2017

STATUS

approved

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Last modified October 15 07:56 EDT 2019. Contains 328026 sequences. (Running on oeis4.)