p, p+6 and p+10 are primes.

Terms

a(0) =7a(1) =13a(2) =31a(3) =37a(4) =61a(5) =73a(6) =97a(7) =103a(8) =157a(9) =223a(10) =271a(11) =307a(12) =373a(13) =433a(14) =457a(15) =607a(16) =733a(17) =751a(18) =853a(19) =877a(20) =1087a(21) =1291a(22) =1297a(23) =1423a(24) =1483a(25) =1543a(26) =1657a(27) =1777a(28) =1861a(29) =1867