Numbers k such that k and k^2 use only the digits 0, 1, 2, 3 and 7.

Terms

a(0) =0a(1) =1a(2) =10a(3) =11a(4) =100a(5) =101a(6) =110a(7) =111a(8) =1000a(9) =1001a(10) =1010a(11) =1011a(12) =1100a(13) =1101a(14) =1110a(15) =10000a(16) =10001a(17) =10010a(18) =10011a(19) =10100a(20) =10101a(21) =10110a(22) =10111a(23) =11000a(24) =11001a(25) =11010a(26) =11100a(27) =11101a(28) =100000a(29) =100001