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

Terms

a(0) =0a(1) =2a(2) =20a(3) =22a(4) =200a(5) =202a(6) =220a(7) =2000a(8) =2002a(9) =2020a(10) =2022a(11) =2200a(12) =2202a(13) =20000a(14) =20002a(15) =20020a(16) =20022a(17) =20200a(18) =20220a(19) =22000a(20) =22002a(21) =22020a(22) =200000a(23) =200002a(24) =200020a(25) =200022a(26) =200200a(27) =200202a(28) =200220a(29) =202000