A010714 Period 2: repeat [4, 9].

4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4, 9, 4

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A176219.

Programs

Mathematica

Table[4 + 5 Mod[n, 2], {n, 0, 50}] (* Jinyuan Wang, Feb 26 2020 *)

PARI

a(n)=4+n%2*5 \\ Charles R Greathouse IV, Dec 21 2011

Formula

G.f.: (4+9x)/((1-x)*(1+x)). - R. J. Mathar, Nov 21 2011

From Wesley Ivan Hurt, Dec 31 2023: (Start)

a(n) = a(n-2) for n>1 with a(0)=4, a(1)=9.

a(n) = (13-5*(-1)^n)/2. (End)