A192308 1-sequence of reduction of (3n) by x^2 -> x+1.

0, 6, 15, 39, 84, 174, 342, 654, 1221, 2241, 4056, 7260, 12876, 22662, 39627, 68907, 119244, 205482, 352770, 603630, 1029825, 1752261, 2974320, 5037624, 8515224, 14367174, 24200007, 40699119, 68348676, 114629286, 192009006, 321250830, 536903421, 896410377

Offset: 1

Author

Clark Kimberling, Jun 27 2011

Keywords

• nonn
• changed

Comments

See A192232 for definition of "k-sequence of reduction of [sequence] by [substitution]".

Crossrefs

Cf. A192232, A192307, A122491.

Programs

Mathematica

(* See A192307. *)

Formula

a(n) = 3*A122491(n+1).

G.f.: 3*x^2*(2-x)/(1-x)/(1-x-x^2)^2. - Colin Barker, Feb 11 2012

Extensions

More terms from Jason Yuen, Aug 23 2025