A304836 a(n) = 27*n^2 - 51*n + 24, n>=1.

0, 30, 114, 252, 444, 690, 990, 1344, 1752, 2214, 2730, 3300, 3924, 4602, 5334, 6120, 6960, 7854, 8802, 9804, 10860, 11970, 13134, 14352, 15624, 16950, 18330, 19764, 21252, 22794, 24390, 26040, 27744, 29502, 31314, 33180, 35100, 37074, 39102, 41184, 43320, 45510, 47754, 50052, 52404

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

Cf. A082040, A304837, A304838.

Sequence in context: A044281 A044662 A205829 * A010018 A256649 A378510

Adjacent sequences: A304833 A304834 A304835 * A304837 A304838 A304839

Keyword

nonn,easy

Author

Emeric Deutsch, May 21 2018

Status

approved