OFFSET
1,2
COMMENTS
a(n) is the number of edges in the hex derived network HDN1(n) from the Manuel et al. reference (see HDN1(4) in Fig. 8).
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
P. Manuel, R. Bharati, I. Rajasingh, and Chris Monica M, On minimum metric dimension of honeycomb networks, J. Discrete Algorithms, 6, 2008, 20-27.
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
From Colin Barker, May 23 2018: (Start)
G.f.: 6*x^2*(5 + 4*x) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>3.
(End)
MAPLE
seq(27*n^2-51*n+24, n = 1 .. 45);
PROG
(GAP) List([1..50], n->27*n^2-51*n+24); # Muniru A Asiru, May 21 2018
(PARI) concat(0, Vec(6*x^2*(5 + 4*x) / (1 - x)^3 + O(x^40))) \\ Colin Barker, May 23 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, May 21 2018
STATUS
approved