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A228702 Wiener index of generalized Fibonacci cube graph Q_n(111). 0
0, 1, 8, 36, 164, 694, 2792, 11008, 42484, 161395, 606000, 2252856, 8307224, 30424076, 110774704, 401307232, 1447463192, 5200692085, 18622103160, 66476800796, 236657676956, 840418968098, 2977799304536, 10529449821312, 37162248493740, 130933420076839 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
There is an explicit formula for a(n) in terms of tribonacci numbers (A000073).
Empirical g.f.: x*(x^2+1)*(x^2+4*x+1) / ((x^3-x^2-x-1)^2*(x^3+x^2+3*x-1)^2). - Colin Barker, Sep 08 2013
PROG
(Magma) /* From Klavzar and Rho paper, Theorem 2.4: */ T:=[n le 3 select Floor(n/3) else Self(n-1)+Self(n-2)+Self(n-3): n in [1..40]]; /* being T=A000073 */ [((268+67*n)*T[n+4]^2-(118+4*n)*T[n+4]*T[n+5]-(50-14*n)*T[n+4]*T[n+6] -(66+7*n)*T[n+5]^2+(90+16*n)*T[n+5]*T[n+6]-(18+6*n)*T[n+6]^2)/484: n in [0..#T-6]]; // Bruno Berselli, Sep 06 2013
CROSSREFS
Cf. A000073.
Sequence in context: A055918 A074404 A221701 * A200667 A200468 A200250
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 06 2013
EXTENSIONS
More terms from Bruno Berselli, Sep 06 2013
STATUS
approved

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Last modified April 19 18:05 EDT 2024. Contains 371798 sequences. (Running on oeis4.)