Numbers whose base-10 representation has the same nonzero number of 5's and 6's.

Terms

a(0) =56a(1) =65a(2) =156a(3) =165a(4) =256a(5) =265a(6) =356a(7) =365a(8) =456a(9) =465a(10) =506a(11) =516a(12) =526a(13) =536a(14) =546a(15) =560a(16) =561a(17) =562a(18) =563a(19) =564a(20) =567a(21) =568a(22) =569a(23) =576a(24) =586a(25) =596a(26) =605a(27) =615a(28) =625a(29) =635