Numbers k such that 7*10^k + 9 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =11a(5) =12a(6) =13a(7) =35a(8) =46a(9) =57a(10) =128a(11) =156a(12) =263a(13) =353a(14) =396a(15) =429a(16) =783a(17) =982a(18) =1058a(19) =1563a(20) =1695a(21) =1816a(22) =1937a(23) =4236a(24) =4431a(25) =6858a(26) =9898a(27) =13145a(28) =16646a(29) =20891