-44716177445domain: ZAppears in sequencesExpansion of g.f. (1-x)(x^2-5x+3)/(x^4-6x^3+13x^2-6x+1).at n=21A105660a(n) = cos(2*n*arcsin(sqrt(3))) = (-1)^n*cosh(2*n*arcsinh(sqrt(2))).at n=11A146311