Numbers k such that k and k^2 use only the digits 0, 2, 3, 4 and 6.

Terms

a(0) =0a(1) =2a(2) =6a(3) =20a(4) =60a(5) =200a(6) =206a(7) =600a(8) =602a(9) =2000a(10) =2006a(11) =2060a(12) =6000a(13) =6002a(14) =6020a(15) =6344a(16) =20000a(17) =20006a(18) =20060a(19) =20600a(20) =20602a(21) =60000a(22) =60002a(23) =60020a(24) =60200a(25) =63440a(26) =200000a(27) =200006a(28) =200060a(29) =200600