54640domain: NAppears in sequencesG.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) / (1-x)^8.at n=13A162596Expansion of Product_{k>=1} ((1 + x^k) * (1 + 3*x^k)).at n=21A266822Expansion of (2*x+1)*(1-x) / ( 1-2*x-4*x^2+6*x^3 ).at n=11A271893