Numbers k such that k and k^2 use only the digits 0, 1, 4, 8 and 9.

Terms

a(0) =0a(1) =1a(2) =9a(3) =10a(4) =90a(5) =99a(6) =100a(7) =109a(8) =141a(9) =441a(10) =900a(11) =901a(12) =990a(13) =999a(14) =1000a(15) =1009a(16) =1049a(17) =1090a(18) =1191a(19) =1410a(20) =4410a(21) =9000a(22) =9001a(23) =9010a(24) =9049a(25) =9900a(26) =9990a(27) =9999a(28) =10000a(29) =10009