1948268domain: NAppears in sequencesTriangle, read by rows, each row n being defined by g.f. Product_{k=1..n} (k + x + 2*k*x^2), for n >= 0.at n=55A322891a(n) = [x^(n-1)] Product_{k=1..n} (k + x + 2*k*x^2), for n >= 1.at n=6A322893