Primes that contain digits 1 and 6 only.

Terms

a(0) =11a(1) =61a(2) =661a(3) =6661a(4) =11161a(5) =16111a(6) =16661a(7) =66161a(8) =111611a(9) =161611a(10) =611111a(11) =616111a(12) =1111661a(13) =1611161a(14) =1616161a(15) =1616611a(16) =1661111a(17) =1661161a(18) =1666111a(19) =6111661a(20) =6116111a(21) =6116161a(22) =6161161a(23) =6611611a(24) =6661111a(25) =6661661a(26) =11111161a(27) =11166611a(28) =11616611