A156346 Palindromic period of length 12: repeat 1,2,-4,4,-2,-1,-1,-2,4,-4,2,1.

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

Offset: 0

Author

Paul Curtz, Feb 08 2009

Keywords

• easy
• sign

Links

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

Crossrefs

Cf. A156283.

Programs

Mathematica

PadRight[{},50,{1,2,-4,4,-2,-1,-1,-2,4,-4,2,1}] (* Harvey P. Dale, May 29 2021 *)

Formula

a(n) == A154811(n) (mod 9).

a(n) = ( (2*A154811(n)) mod 9 ) - A154811(n).

G.f.: -(x-1)*(x^4+3*x^3-x^2+3*x+1) / ( (1+x^2)*(x^4-x^2+1) ). - R. J. Mathar, Mar 08 2011