1907137domain: NAppears in sequencesExpansion of (1-x)^(-1)/(1-x+2*x^2).at n=42A077876Expansion of g.f.: (1+3*x^2)/((1-x)*(1+x+2*x^2)*(1-x+2*x^2)).at n=42A107443Expansion of g.f.: (1+3*x^2)/((1-x)*(1+x+2*x^2)*(1-x+2*x^2)).at n=43A107443Expansion of g.f. (1+3*x)/((1-x)*(1+3*x+4*x^2)).at n=21A174565