Numbers k such that k and k^2 use only the digits 0, 2, 5, 6 and 8.

Terms

a(0) =0a(1) =5a(2) =25a(3) =50a(4) =225a(5) =250a(6) =255a(7) =500a(8) =505a(9) =825a(10) =2250a(11) =2255a(12) =2500a(13) =2550a(14) =2555a(15) =2585a(16) =2865a(17) =5000a(18) =5005a(19) =5025a(20) =5050a(21) =8250a(22) =22500a(23) =22550a(24) =22805a(25) =22865a(26) =25000a(27) =25005a(28) =25025a(29) =25500