Numbers k such that k and k^2 use only the digits 4, 5, 6, 8 and 9.

Terms

a(0) =8a(1) =69684a(2) =946888a(3) =6669684a(4) =6988884a(5) =66996684a(6) =94598866a(7) =666696684a(8) =666699684a(9) =698988884a(10) =946566884a(11) =948496684a(12) =6669966684a(13) =6855558664a(14) =6998898884a(15) =9458585866a(16) =66666966684a(17) =66666996684a(18) =68446655864a(19) =69684686664a(20) =69888946684a(21) =69898966864a(22) =69988966884a(23) =94649646886a(24) =94656988884a(25) =666699666684a(26) =669998855886a(27) =685555646658