Sums of 4 distinct powers of 10.

Terms

a(0) =1111a(1) =10111a(2) =11011a(3) =11101a(4) =11110a(5) =100111a(6) =101011a(7) =101101a(8) =101110a(9) =110011a(10) =110101a(11) =110110a(12) =111001a(13) =111010a(14) =111100a(15) =1000111a(16) =1001011a(17) =1001101a(18) =1001110a(19) =1010011a(20) =1010101a(21) =1010110a(22) =1011001a(23) =1011010a(24) =1011100a(25) =1100011a(26) =1100101a(27) =1100110a(28) =1101001a(29) =1101010