Exponent of 4 (value of i) in n-th number of form 4^i*10^j.

Terms

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