Numbers with digits 4 and 8 only.

Terms

a(0) =4a(1) =8a(2) =44a(3) =48a(4) =84a(5) =88a(6) =444a(7) =448a(8) =484a(9) =488a(10) =844a(11) =848a(12) =884a(13) =888a(14) =4444a(15) =4448a(16) =4484a(17) =4488a(18) =4844a(19) =4848a(20) =4884a(21) =4888a(22) =8444a(23) =8448a(24) =8484a(25) =8488a(26) =8844a(27) =8848a(28) =8884a(29) =8888