52899domain: NAppears in sequencesSquarefree numbers k with largest prime factor = floor(sqrt(k)).at n=36A071311Squarefree numbers of the form (prime(k)+1)*(prime(k+1)+1)/4.at n=20A079095a(n) = (2*n+1)*(n+1)*(2*n^2+3*n-1).at n=10A123197G.f. is the polynomial (Product_{k=1..21} (1 - x^(3*k)))/(1-x)^21.at n=5A162646