571580604871domain: NAppears in sequencesA nonlinear recurrence: a(n) = a(n-1)^2 - 3*a(n-1) + 3 (for n>1).at n=6A000289P_n(k) with P_0(z) = z+1 and P_n(z) = z + P_(n-1)(z)*(P_(n-1)(z)-z) for n>1; square array P_n(k), n>=0, k>=0, read by antidiagonals.at n=41A177888