A010707 Period 2: repeat (3,9).

3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3, 9, 3

Offset

0,1

Comments

Continued fraction expansion of A176108. - R. J. Mathar, Mar 08 2012

Decimal expansion of 13/33. - Elmo R. Oliveira, Oct 12 2025

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*(-1)^n + 6. - Paolo P. Lava, Oct 20 2006

G.f.: 3*(1+3*x)/((1-x)*(1+x)). - R. J. Mathar, Nov 21 2011

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

E.g.f.: 3*cosh(x) + 9*sinh(x).

a(n) = 3*A010684(n). (End)

Mathematica

PadRight[{}, 120, {3, 9}] (* Harvey P. Dale, Nov 07 2017 *)

Prog

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

Crossrefs

Cf. A010684, A176108.

Sequence in context: A231828 A268580 A179802 * A097665 A388638 A284564

Adjacent sequences: A010704 A010705 A010706 * A010708 A010709 A010710

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved