A289443 a(0) = 2, a(1) = 6; thereafter a(n) = 3*n^2.

2, 6, 12, 27, 48, 75, 108, 147, 192, 243, 300, 363, 432, 507, 588, 675, 768, 867, 972, 1083, 1200, 1323, 1452, 1587, 1728, 1875, 2028, 2187, 2352, 2523, 2700, 2883, 3072, 3267, 3468, 3675, 3888, 4107, 4332, 4563, 4800, 5043, 5292, 5547, 5808, 6075, 6348, 6627, 6912, 7203, 7500

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Radim Hosek, Construction and shape optimization of simplical meshes in d-dimensional space, arXiv preprint arXiv:1606.09113 [math.MG], 2016.

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

G.f.: (2 + 7*x^3 - 3*x^4)/(1 - x)^3. - Vincenzo Librandi, Jul 08 2017

E.g.f.: 2 + 3*x + 3*exp(x)*x*(1 + x). - Stefano Spezia, Dec 17 2022

Mathematica

Join[{2, 6}, Table[3 n^2, {n, 2, 50}]] (* or *) {2, 6}~Join~LinearRecurrence[{3, -3, 1}, {12, 27, 48}, 50] (* Vincenzo Librandi, Jul 08 2017 *)

Prog

(Magma) [2, 6] cat [3*n^2: n in [2..60]]; // Vincenzo Librandi, Jul 08 2017
(PARI) a(n)=3*n^2+if(n<2, n+2) \\ Charles R Greathouse IV, Oct 21 2022

Crossrefs

Essentially the same as A033428.

Sequence in context: A350294 A052971 A364423 * A029863 A091919 A059078

Adjacent sequences: A289440 A289441 A289442 * A289444 A289445 A289446

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 07 2017

Status

approved