Numbers using only digits 1 and 6.

Terms

a(0) =1a(1) =6a(2) =11a(3) =16a(4) =61a(5) =66a(6) =111a(7) =116a(8) =161a(9) =166a(10) =611a(11) =616a(12) =661a(13) =666a(14) =1111a(15) =1116a(16) =1161a(17) =1166a(18) =1611a(19) =1616a(20) =1661a(21) =1666a(22) =6111a(23) =6116a(24) =6161a(25) =6166a(26) =6611a(27) =6616a(28) =6661a(29) =6666