Euclid-Mullin sequence: a(1) = 2, a(n+1) is smallest prime factor of 1 + Product_{k=1..n} a(k).

Terms

a(0) =2a(1) =3a(2) =7a(3) =43a(4) =13a(5) =53a(6) =5a(7) =6221671a(9) =139a(10) =2801a(11) =11a(12) =17a(13) =5471a(14) =52662739a(15) =23003a(17) =37a(18) =1741a(19) =1313797957a(20) =887a(21) =71a(22) =7127a(23) =109a(24) =23a(25) =97a(26) =159227a(28) =103a(29) =1079990819a(30) =9539a(31) =3143065813a(32) =29