55548domain: NAppears in sequencesNumber of lucky twins <= 10^n.at n=7A055724Numbers k such that k and k^2 use only the digits 0, 3, 4, 5 and 8.at n=4A136928a(n) is the number of positive integer solutions of n*x*y*z*v*w = (x + n) * (y + n) * (z + n) * (v + n) * (w + n), x <= y <= z <= v <= w.at n=7A381644