Least non-divisor of n.

Terms

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