3147277domain: NAppears in sequencesExpansion of -x * (21*x^7+65*x^6+77*x^5+39*x^4-17*x^3-38*x^2-11*x-1) / ((x+1) * (x^3+x^2-1) * (x^4+2*x^3+x^2+x-1)).at n=18A122015