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

Terms

a(0) =0a(1) =1a(2) =2a(3) =10a(4) =11a(5) =12a(6) =20a(7) =21a(8) =49a(9) =100a(10) =101a(11) =102a(12) =110a(13) =120a(14) =149a(15) =200a(16) =201a(17) =210a(18) =212a(19) =490a(20) =499a(21) =1000a(22) =1001a(23) =1002a(24) =1010a(25) =1011a(26) =1012a(27) =1020a(28) =1021a(29) =1049