OFFSET
1,1
COMMENTS
The Hosoya-Wiener polynomial of the graph is n(6+6t+6t^2+3t^3)+(1+2t+2t^2+t^3)^2*(t^{4n+1}-nt^5+nt-t)/(t^4-1)^2.
REFERENCES
Y. Dou, H. Bian, H. Gao, and H. Yu, The polyphenyl chains with extremal edge-Wiener indices, MATCH Commun. Math. Comput. Chem., 64, 2010, 757-766.
LINKS
H. Deng, Wiener indices of spiro and polyphenyl hexagonal chains, arXiv:1006.5488
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
a(n) = 3n(16n^3 + 8n^2 - 5n +9)/2.
G.f.: 3*x*(3*x^3-92*x^2-89*x-14)/(x-1)^5. [Colin Barker, Oct 30 2012]
MAPLE
seq(3*n*(16*n^3+8*n^2-5*n+9)*(1/2), n=1..30);
MATHEMATICA
LinearRecurrence[{5, -10, 10, -5, 1}, {42, 477, 2241, 6846, 16380}, 30] (* Jean-François Alcover, Sep 23 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Oct 26 2012
STATUS
approved