n in base whose greedy place values are quarter-squares (A002620).

Terms

a(0) =0a(1) =1a(2) =10a(3) =11a(4) =100a(5) =101a(6) =1000a(7) =1001a(8) =1010a(9) =10000a(10) =10001a(11) =10010a(12) =100000a(13) =100001a(14) =100010a(15) =100011a(16) =1000000a(17) =1000001a(18) =1000010a(19) =1000011a(20) =10000000a(21) =10000001a(22) =10000010a(23) =10000011a(24) =10000100a(25) =100000000a(26) =100000001a(27) =100000010a(28) =100000011a(29) =100000100