Numbers k such that k and k^2 use only the digits 0, 4, 5, 7 and 8.

Terms

a(0) =0a(1) =88a(2) =878a(3) =880a(4) =888a(5) =7588a(6) =8780a(7) =8800a(8) =8880a(9) =74078a(10) =75878a(11) =75880a(12) =87800a(13) =88000a(14) =88800a(15) =740578a(16) =740588a(17) =740780a(18) =755478a(19) =758780a(20) =758800a(21) =840088a(22) =878000a(23) =880000a(24) =880088a(25) =888000a(26) =7405780a(27) =7405880a(28) =7407800a(29) =7554780