-156856domain: ZAppears in sequencesExpansion of 1/(1-x+2*x^2+x^3).at n=26A077955Expansion of 1/(1+x+2*x^2-x^3).at n=26A077978a(n+3) = -a(n+2) - 2*a(n+1) + a(n) with a(0)=0, a(1)=0, a(2)=1.at n=28A276229