Leading digit of 2^n.

Terms

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