Least prime divisor of 2*prime(n)-1.

Terms

a(0) =3a(1) =5a(2) =3a(3) =13a(4) =3a(5) =5a(6) =3a(7) =37a(8) =3a(9) =3a(10) =61a(11) =73a(12) =3a(13) =5a(14) =3a(15) =3a(16) =3a(17) =11a(18) =7a(19) =3a(20) =5a(21) =157a(22) =3a(23) =3a(24) =193a(25) =3a(26) =5a(27) =3a(28) =7a(29) =3