a(n) = exponent of the n-th nontrivial prime power A025475(n).

Terms

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