Primes followed by a gap of 6, i.e., next prime is p + 6.

Terms

a(0) =23a(1) =31a(2) =47a(3) =53a(4) =61a(5) =73a(6) =83a(7) =131a(8) =151a(9) =157a(10) =167a(11) =173a(12) =233a(13) =251a(14) =257a(15) =263a(16) =271a(17) =331a(18) =353a(19) =367a(20) =373a(21) =383a(22) =433a(23) =443a(24) =503a(25) =541a(26) =557a(27) =563a(28) =571a(29) =587