A017185 a(n) = 9*n + 2.

2, 11, 20, 29, 38, 47, 56, 65, 74, 83, 92, 101, 110, 119, 128, 137, 146, 155, 164, 173, 182, 191, 200, 209, 218, 227, 236, 245, 254, 263, 272, 281, 290, 299, 308, 317, 326, 335, 344, 353, 362, 371, 380, 389, 398, 407, 416, 425, 434, 443, 452, 461, 470, 479

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

Numbers whose digital root is 2. - Cino Hilliard, Dec 26 2006

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..5000
• Tanya Khovanova, Recursive Sequences.
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Cf. A008591, A016789, A017173.

Programs

Magma

[9*n+2: n in [0..60]]; // Vincenzo Librandi, Jul 23 2011

Mathematica

Range[2, 1000, 9] (* Vladimir Joseph Stephan Orlovsky, May 28 2011 *)
LinearRecurrence[{2,-1},{2,11},60] (* Harvey P. Dale, Jun 09 2023 *)

PARI

a(n)=9*n+2 \\ Charles R Greathouse IV, Oct 07 2015

Formula

G.f.: (2 + 7*x)/(x - 1)^2. - R. J. Mathar, Jul 14 2016

E.g.f.: exp(x)*(2 + 9*x). - Stefano Spezia, Dec 07 2024

From Elmo R. Oliveira, Apr 12 2025: (Start)

a(n) = 2*a(n-1) - a(n-2).

a(n) = A016789(3*n). (End)

Extensions

More terms from Cino Hilliard, Dec 26 2006