Smallest primitive factor of 2^(2n+1) + 1.

Terms

a(0) =3a(1) =1a(2) =11a(3) =43a(4) =19a(5) =683a(6) =2731a(7) =331a(8) =43691a(9) =174763a(10) =5419a(11) =2796203a(12) =251a(13) =87211a(14) =59a(15) =715827883a(16) =67a(17) =281a(18) =1777a(19) =22366891a(20) =83a(22) =18837001a(23) =283a(25) =307a(26) =107a(27) =2971a(28) =571a(29) =2833a(31) =77158673929a(32) =131