OFFSET
2,1
COMMENTS
a(2), a(3), ..., a(6) have been checked by the direct computation of the Wiener index (using Maple).
LINKS
Harvey P. Dale, Table of n, a(n) for n = 2..1000
M. Eliasi, A. Iranmanesh, The hyper-Wiener index of the generalized hierarchical product of graphs, Discrete Appl. Math., 159, 2011, 866-871.
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = 2*n*(1 + 2*n + 2*n^2).
G.f. = 2*x^2*(26-29*x+20*x^2-5*x^3)/(1-x)^4.
The Hosoya-Wiener polynomial of TUHC_6[2n,2] is n*(2*t^n*(1 + t)^2 + t^4 - t^3 - 3*t^2 - 5*t)/(t - 1).
MAPLE
a := proc (n) options operator, arrow: 2*n*(1+2*n+2*n^2) end proc: seq(a(n), n = 2 .. 40);
MATHEMATICA
Table[2n(1+2n+2n^2), {n, 2, 40}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {52, 150, 328, 610}, 40] (* Harvey P. Dale, Jan 15 2015 *)
PROG
(PARI) a(n)=2*n*(1+2*n+2*n^2) \\ Charles R Greathouse IV, Oct 18 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Jul 25 2013
STATUS
approved