A216106 The Wiener index of the tetrameric 1,3-adamantane TA(n) (see the Fath-Tabar et al. reference).

96, 652, 1968, 4344, 8080, 13476, 20832, 30448, 42624, 57660, 75856, 97512, 122928, 152404, 186240, 224736, 268192, 316908, 371184, 431320, 497616, 570372, 649888, 736464, 830400, 931996, 1041552, 1159368, 1285744, 1420980

Offset

1,1

Comments

The Hosoya-Wiener polynomial of TA(n) is n(10+12t+18t^2+12t^3+3t^4)+(1+3t+3t^2+3t^3)^2*(t^{3n+1}-nt^4+nt-1)/(t^3-1)^2.

Links

Table of n, a(n) for n=1..30.

G. H. Fath-Tabar, A. Azad, and N. Elahinezhad, Some topological indices of tetrameric 1,3-adamantane, Iranian J. Math. Chemistry, 1, No. 1, 2010, 111-118.

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

a(n) = 50n^3 + 80n^2 - 34n.

G.f.: -4*x*(16*x^2-67*x-24)/(x-1)^4. [Colin Barker, Oct 31 2012]

Maple

seq(50*n^3+80*n^2-34*n, n=1..30);

Crossrefs

Cf. A216107.

Sequence in context: A251167 A251160 A233029 * A268795 A232405 A269032

Adjacent sequences: A216103 A216104 A216105 * A216107 A216108 A216109

Keyword

nonn,easy

Author

Emeric Deutsch, Oct 26 2012

Status

approved