Numbers k such that k and k^2 use only the digits 0, 6, 7, 8 and 9.

Terms

a(0) =0a(1) =887a(2) =8870a(3) =8886a(4) =8887a(5) =87676a(6) =87687a(7) =88700a(8) =88860a(9) =88870a(10) =88887a(11) =89867a(12) =876760a(13) =876870a(14) =887000a(15) =887676a(16) =888600a(17) =888700a(18) =888870a(19) =898670a(20) =989897a(21) =7788887a(22) =7796076a(23) =8767600a(24) =8768700a(25) =8870000a(26) =8876760a(27) =8886000a(28) =8887000a(29) =8888700