A173512 a(n) = 8*n + 4 + n mod 2.

4, 13, 20, 29, 36, 45, 52, 61, 68, 77, 84, 93, 100, 109, 116, 125, 132, 141, 148, 157, 164, 173, 180, 189, 196, 205, 212, 221, 228, 237, 244, 253, 260, 269, 276, 285, 292, 301, 308, 317, 324, 333, 340, 349, 356, 365, 372, 381, 388, 397, 404, 413, 420, 429, 436

Offset: 0

Author

Reinhard Zumkeller, Feb 20 2010

Keywords

• nonn

Comments

First differences of A173511;

a(n+1) - a(n) = A010729(n+1).

Links

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

Programs

Magma

[8*n+4+n mod 2: n in [0..60]]; // Vincenzo Librandi, Nov 29 2016

Mathematica

LinearRecurrence[{1, 1, -1}, {4, 13, 20}, 60] (* Vincenzo Librandi, Nov 29 2016 *)

Formula

G.f.: (4 + 9*x + 3*x^2)/((1 + x)*(1 - x)^2). - Philippe Deléham, Nov 29 2016