Numbers k such that k and k^2 use only the digits 0, 1, 4, 5 and 6.

Terms

a(0) =0a(1) =1a(2) =4a(3) =10a(4) =40a(5) =100a(6) =400a(7) =1000a(8) =1051a(9) =4000a(10) =4051a(11) =6416a(12) =6451a(13) =6454a(14) =10000a(15) =10510a(16) =40000a(17) =40510a(18) =64160a(19) =64510a(20) =64540a(21) =100000a(22) =100501a(23) =100504a(24) =105100a(25) =400000a(26) =400501a(27) =405100a(28) =641600a(29) =645100