Exponent of 5 (value of j) in n-th number of form 2^i*5^j.

Terms

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