A010702 Period 2: repeat (3,4).

3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3, 4, 3

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

Continued fraction expansion of A176102. - R. J. Mathar, Mar 08 2012

Also decimal expansion of 34/99. - Nicolas Bělohoubek, Nov 12 2021

Links

• Matthew House, Table of n, a(n) for n = 0..10000
• Index entries for linear recurrences with constant coefficients, signature (0,1).

Crossrefs

Cf. A047355 (partial sums), A176102.

Cf. A010695, A010696.

Programs

Haskell

a010702 = (+ 3) . (`mod` 2)
a010702_list = cycle [3,4]  -- Reinhard Zumkeller, Jul 05 2012

Magma

[3 + (n mod 2) : n in [0..100]]; // Wesley Ivan Hurt, Jul 24 2014

Magma

&cat[[3,4]: n in [0..50]]; // Vincenzo Librandi, Aug 01 2015

Maple

A010702:=n->3+(n mod 2): seq(A010702(n), n=0..100); # Wesley Ivan Hurt, Jul 24 2014

Mathematica

3 + Mod[Range[0, 100], 2] (* Wesley Ivan Hurt, Jul 24 2014 *)
PadRight[{}, 100, {3, 4}] (* Vincenzo Librandi, Aug 01 2015 *)

PARI

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

Python

def A010702(n): return 3 + (n & 1) # Chai Wah Wu, May 25 2022

Formula

G.f.: (3+4*x)/(1-x^2). - Jaume Oliver Lafont, Mar 20 2009

a(n) = floor((n+1)*7/2) - floor((n)*7/2). - Hailey R. Olafson, Jul 23 2014

a(n) = 3 + (n mod 2) = 4 - ((n+1) mod 2). - Wesley Ivan Hurt, Jul 24 2014

From Nicolas Bělohoubek, Nov 12 2021: (Start)

a(n) = 12/a(n-1). See also A010696.

a(n) = 7 - a(n-1). See also A010695. (End)

a(n) = (7-(-1)^n)/2. - Aaron J Grech, Jul 28 2024