Numbers k such that k^2 has only digits 0, 4 and 8.

Terms

a(0) =0a(1) =2a(2) =20a(3) =22a(4) =200a(5) =202a(6) =220a(7) =298a(8) =2000a(9) =2002a(10) =2020a(11) =2022a(12) =2200a(13) =2202a(14) =2980a(15) =20000a(16) =20002a(17) =20020a(18) =20022a(19) =20200a(20) =20220a(21) =22000a(22) =22002a(23) =22020a(24) =28998a(25) =29800a(26) =200000a(27) =200002a(28) =200020a(29) =200022