Numbers k such that k-6, k, and k+6 are primes.

Terms

a(0) =11a(1) =13a(2) =17a(3) =23a(4) =37a(5) =47a(6) =53a(7) =67a(8) =73a(9) =103a(10) =107a(11) =157a(12) =173a(13) =233a(14) =257a(15) =263a(16) =277a(17) =353a(18) =373a(19) =563a(20) =593a(21) =607a(22) =613a(23) =647a(24) =653a(25) =733a(26) =947a(27) =977a(28) =1097a(29) =1103