Numbers k such that 409*2^k+1 is prime.

Terms

a(0) =2a(1) =6a(2) =18a(3) =110a(4) =186a(5) =318a(6) =398a(7) =1922a(8) =3290a(9) =4346a(10) =5042a(11) =6638a(12) =8306a(13) =59066a(14) =66758a(15) =182198a(16) =214406a(17) =260810a(18) =709350a(19) =947018a(20) =1384346a(21) =1546542a(22) =2360166