52715domain: NAppears in sequencesNumbers k such that k and k^2 use only the digits 1, 2, 5, 7 and 8.at n=12A137008a(n) = 3*a(n-1) + a(n-3) with a(0)=1, a(1)=2, a(2)=6.at n=10A183188Triangle read by rows, coefficients of generalized Eulerian polynomials F_{3;n}(x).at n=11A292605