Smallest positive integer k such that 2^k has no '0' in the last n digits of its ternary expansion.

Terms

a(0) =1a(1) =2a(2) =4a(3) =10a(4) =15a(5) =15a(6) =15a(7) =15a(8) =15a(9) =15a(10) =50a(11) =50a(12) =101a(13) =101a(14) =101a(15) =101a(16) =143a(17) =143a(18) =143a(19) =143a(20) =143a(21) =143a(22) =143a(23) =143a(24) =143a(25) =1916a(26) =1916a(27) =1916a(28) =1916a(29) =1916