Numbers k such that k and k^2 use only the digits 0, 2, 4, 6 and 9.

Terms

a(0) =0a(1) =2a(2) =20a(3) =64a(4) =200a(5) =264a(6) =492a(7) =640a(8) =964a(9) =2000a(10) =2064a(11) =2640a(12) =4902a(13) =4920a(14) =4992a(15) =6400a(16) =9640a(17) =20000a(18) =20602a(19) =20640a(20) =20992a(21) =24992a(22) =26400a(23) =49020a(24) =49200a(25) =49902a(26) =49920a(27) =49992a(28) =64000a(29) =96400