A007945 Expansion of g.f. (2-x-2*x^2)/((1-x)*(1-x+x^2)).

2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3, 0, -4, -5, -2, 2, 3

Offset: 0

Author

N. J. A. Sloane

Keywords

• sign
• easy

Comments

A period 6 sequence. - Christian Krause, Dec 07 2023

Links

• Index entries for linear recurrences with constant coefficients, signature (2,-2,1).

Formula

G.f.: (2-x-2*x^2)/((1-x)*(1-x+x^2)).

a(n) = a(n-1) - a(n-2) - 1. - Christian Krause, Dec 07 2023

a(n) = 5*sin(n*Pi/3)/sqrt(3) + 3*cos(n*Pi/3) - 1. - Wesley Ivan Hurt, Dec 09 2023