Numbers k such that 209*2^k+1 is prime.

Terms

a(0) =1a(1) =5a(2) =11a(3) =13a(4) =65a(5) =113a(6) =299a(7) =335a(8) =1235a(9) =1991a(10) =2861a(11) =3295a(12) =3343a(13) =3901a(14) =5545a(15) =9125a(16) =10769a(17) =14303a(18) =19433a(19) =28535a(20) =76855a(21) =206821a(22) =207223a(23) =530729a(24) =1172111a(25) =1992071