Numbers k such that k and k^2 use only the digits 0, 3, 6 and 9.

Terms

a(0) =0a(1) =3a(2) =6a(3) =30a(4) =60a(5) =63a(6) =300a(7) =306a(8) =600a(9) =603a(10) =630a(11) =3000a(12) =3006a(13) =3060a(14) =6000a(15) =6003a(16) =6030a(17) =6300a(18) =30000a(19) =30006a(20) =30060a(21) =30600a(22) =60000a(23) =60003a(24) =60030a(25) =60300a(26) =63000a(27) =300000a(28) =300006a(29) =300060