Least odd prime divisor of prime(n) + 1, or 1 if prime(n) + 1 is a power of 2.

Terms

a(0) =3a(1) =1a(2) =3a(3) =1a(4) =3a(5) =7a(6) =3a(7) =5a(8) =3a(9) =3a(10) =1a(11) =19a(12) =3a(13) =11a(14) =3a(15) =3a(16) =3a(17) =31a(18) =17a(19) =3a(20) =37a(21) =5a(22) =3a(23) =3a(24) =7a(25) =3a(26) =13a(27) =3a(28) =5a(29) =3