583078domain: NAppears in sequencesExpansion of (1 - x + x^2)*(1 + x + x^2 - x^3 + 2*x^4)/((1 - x)*(1 + x)^2*(1 + x^2)*(1 + x - x^2 + x^3)).at n=20A104237Expansion of (-x+2*x^2-x^3-x^4-2*x^5)/(-1+3*x-2*x^2-x^4+x^5).at n=22A221949