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

Terms

a(0) =4a(1) =8a(2) =16a(3) =28a(4) =40a(5) =52a(6) =80a(7) =148a(8) =328a(9) =8464a(10) =11704a(11) =52372a(12) =60172a(13) =675232a(14) =692692a(15) =921484