Positive numbers n such that n and phi(n) contain digits 0 and 1 only.

Terms

a(0) =1a(1) =11a(2) =101a(3) =1111a(4) =10111a(5) =101111a(6) =1011001a(7) =1100101a(8) =10010101a(9) =10011101a(10) =10100011a(11) =10101101a(12) =10110011a(13) =10111001a(14) =11000111a(15) =11100101a(16) =11110111a(17) =11111101a(18) =100100111a(19) =100111001a(20) =101001001a(21) =101001011a(22) =101100011a(23) =101101111a(24) =101111011a(25) =101111111a(26) =110010101a(27) =110101001