A158137 Period 9: repeat [-2,4,-2,4,-2,-2,1,1,-2].

-2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2, 4, -2, -2, 1, 1, -2, -2, 4, -2

Offset: 0

Author

Paul Curtz, Mar 13 2009

Keywords

• sign
• easy
• less

Comments

Rotated by 7 places, the period is palindromic: 1,-2,-2,4,-2,4,-2,-2,1.

Links

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

Crossrefs

Cf. A156346.

Programs

Mathematica

PadRight[{},120,{-2,4,-2,4,-2,-2,1,1,-2}] (* Harvey P. Dale, Dec 11 2018 *)

PARI

a(n)=[-2,4,-2,4,-2,-2,1,1,-2][n%9+1] \\ Charles R Greathouse IV, Jul 13 2016

Formula

a(n)= A158090(n)-2 = A158090(n)-A007395(n+1).

G.f.: (-2+2*x+4*x^3+x^6+2*x^4+2*x^7)/((1+x+x^2)*(x^6+x^3+1)). a(n)= -a(n-1)-a(n-2)-a(n-3)-a(n-4)-a(n-5)-a(n-6)-a(n-7)-a(n-8). - R. J. Mathar, Apr 09 2009

Extensions

Edited and extended by R. J. Mathar, Apr 09 2009