10000400001domain: NAppears in sequencesNumbers k such that k^2 contains only digits {0,1,8}, not ending with zero.at n=28A058421Numbers k such that k and k^2 use only the digits 0, 1, 4 and 8.at n=24A136866a(n) = (10^n)^2 + 4*(10^n) + 1.at n=5A225810