

A305063


a(n) = 110*2^n + 118.


3



228, 338, 558, 998, 1878, 3638, 7158, 14198, 28278, 56438, 112758, 225398, 450678, 901238, 1802358, 3604598, 7209078, 14418038, 28835958, 57671798, 115343478, 230686838, 461373558, 922746998, 1845493878, 3690987638, 7381975158, 14763950198, 29527900278, 59055800438, 118111600758, 236223201398
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,1


COMMENTS

a(n)(n>=0) is the second Zagreb index of the dendrimer graph K[n], defined pictorially in the Ghorbani et al. reference (see Figs. 9, 10, and 11).
The second Zagreb index of a simple connected graph is the sum of the degree products d(i)d(j) over all edges ij of the graph.
The Mpolynomial of K[n] is M(K[n]; x, y) = 2*2^n*x*y^3 + 2*(2^n + 2)*x^2*y^2 + (2^4*2^n 4)*x^2*y^3 + 14*x^3*y^3.


LINKS

Table of n, a(n) for n=0..31.
E. Deutsch and Sandi Klavzar, Mpolynomial and degreebased topological indices, Iranian J. Math. Chemistry, 6, No. 2, 2015, 93102.
M. Ghorbani, K. Malekjani, and A. Khaki, Eccentric connectivity index of some dendrimer graphs, Iranian J. of Math. Chemistry, 3, Supplement 1, 2012, s7  s18.
Index entries for linear recurrences with constant coefficients, signature (3,2).


FORMULA

G.f.: (228  346*x)/((1  2*x)*(1  x)).  Vincenzo Librandi, May 25 2018
a(n) = 3*a(n1)  2* a(n2).  Vincenzo Librandi, May 25 2018


MAPLE

seq(110*2^n+118, n = 0 .. 40);


MATHEMATICA

Table[110 2^n + 118, {n, 0, 31}] (* Vincenzo Librandi, May 25 2018 *)


PROG

(Magma) [110*2^n+118: n in [0..40]]; // Vincenzo Librandi, May 25 2018


CROSSREFS

Cf. A305060, A305061, A305062.
Sequence in context: A190027 A090943 A252451 * A258550 A335269 A252228
Adjacent sequences: A305060 A305061 A305062 * A305064 A305065 A305066


KEYWORD

nonn,easy


AUTHOR

Emeric Deutsch, May 24 2018


STATUS

approved



