A010700 Period 2: repeat (2,10).

2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10, 2, 10

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

Continued fraction expansion of A176057. - R. J. Mathar, Mar 08 2012

Links

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

Crossrefs

Cf. A010679: 3^(1-(-1)^n) - 1.

Equals 2 + A010679 = 2 + 8*A000035.

Programs

Magma

&cat [[2,10]^^35]; // Bruno Berselli, Dec 29 2015

Maple

A010700 := n -> 2 + irem(n,2)*8; # M. F. Hasler, Feb 27 2020

Mathematica

PadRight[{}, 100, {2, 10}] (* M. F. Hasler, Feb 27 2020 *)

PARI

a(n)=2+n%2*8 \\ Charles R Greathouse IV, Dec 21 2011

PARI

apply( {A010700(n)=2+bittest(n,0)<<3}, [0..99]) \\ M. F. Hasler, Feb 27 2020

Formula

a(n) = -4*(-1)^n + 6. Paolo P. Lava, Oct 20 2006

G.f. (2+10*x)/((1-x)*(1+x)). - R. J. Mathar, Nov 21 2011

a(n) = 3^(1-(-1)^n) + 1. - Bruno Berselli, Dec 29 2015

a(n) = 2 + 8*(n mod 2) = 2 + 8*A000035(n). - M. F. Hasler, Feb 27 2020