Least prime dividing 2^n+3.

Terms

a(0) =2a(1) =5a(2) =7a(3) =11a(4) =19a(5) =5a(6) =67a(7) =131a(8) =7a(9) =5a(10) =13a(11) =7a(12) =4099a(13) =5a(14) =7a(15) =32771a(16) =65539a(17) =5a(18) =262147a(19) =29a(20) =7a(21) =5a(22) =13a(23) =7a(24) =1549a(25) =5a(26) =7a(27) =4057a(28) =268435459a(29) =5