Numbers k such that (8*10^k - 77)/3 is prime.

Terms

a(0) =2a(1) =4a(2) =5a(3) =6a(4) =15a(5) =18a(6) =43a(7) =45a(8) =55a(9) =60a(10) =105a(11) =128a(12) =180a(13) =207a(14) =271a(15) =479a(16) =869a(17) =1220a(18) =1478a(19) =1937a(20) =4003a(21) =4213a(22) =5503a(23) =9562a(24) =11388a(25) =13120a(26) =34049a(27) =47178a(28) =156371a(29) =271039