A010725 - OEIS

A010725

Period 2: repeat (6,9).

6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6, 9, 6

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

LINKS

Table of n, a(n) for n=0..80.

Index entries for linear recurrences with constant coefficients, signature (0,1).

FORMULA

a(n) = -(3/2)*(-1)^n + 15/2. - Paolo P. Lava, Oct 27 2006

G.f.: ( -6-9*x ) / ( (x-1)*(1+x) ). - R. J. Mathar, Nov 21 2011

a(n) = 6 + 2^(1-(-1)^n) - 1. - Vincenzo Librandi, Feb 27 2020

MATHEMATICA

Table[6 + 3 Mod[n, 2], {n, 0, 50}] (* Jinyuan Wang, Feb 26 2020 *)

PROG

(PARI) a(n)=6+n%2*3 \\ Charles R Greathouse IV, Dec 21 2011

(Magma) &cat [[6, 9]^^50]; // Vincenzo Librandi, Feb 27 2020

CROSSREFS

Cf. A176402.

Sequence in context: A159691 A118947 A023410 * A193594 A011480 A283743

Adjacent sequences: A010722 A010723 A010724 * A010726 A010727 A010728

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved