Numbers k such that k and k^2 use only the digits 0, 1, 2 and 7.

Terms

a(0) =0a(1) =1a(2) =10a(3) =11a(4) =100a(5) =101a(6) =110a(7) =1000a(8) =1001a(9) =1010a(10) =1011a(11) =1100a(12) =1101a(13) =10000a(14) =10001a(15) =10010a(16) =10011a(17) =10100a(18) =10110a(19) =11000a(20) =11001a(21) =11010a(22) =100000a(23) =100001a(24) =100010a(25) =100011a(26) =100100a(27) =100101a(28) =100110a(29) =101000