The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 S. Klavzar and Y. Rho, On the Wiener index of generalized Fibonacci cubes and Lucas cubes, preprint (2013). 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 Adjacent sequences:  A228699 A228700 A228701 * A228703 A228704 A228705 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 06 2013 EXTENSIONS More terms from Bruno Berselli, Sep 06 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 4 15:36 EST 2021. Contains 349526 sequences. (Running on oeis4.)