A172526 a(n)=floor(3*n^2*(2+sqrt(3))).

11, 44, 100, 179, 279, 403, 548, 716, 906, 1119, 1354, 1612, 1892, 2194, 2519, 2866, 3235, 3627, 4041, 4478, 4937, 5418, 5922, 6448, 6997, 7568, 8161, 8777, 9415, 10076, 10759, 11464, 12192, 12942, 13715, 14510, 15327, 16167, 17029, 17913, 18820

Offset: 1

Author

Vincenzo Librandi, Feb 06 2010

Keywords

• nonn

Comments

Approximate area of the dodecahedron of side n=(1,2,3,4,...).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A071401.

Programs

Magma

[Floor(3*n^2*(2+Sqrt(3))): n in [1..50]]; // Vincenzo Librandi, Aug 20 2014

Mathematica

With[{c=3(2+Sqrt[3])},Floor[c Range[50]^2]]  (* Harvey P. Dale, Apr 01 2011 *)
f[n_]:=Floor[3 n^2 (2 + Sqrt[3])]; Array[f, 50, 1] (* Vincenzo Librandi, Aug 20 2014 *)