Xmas tree primes.

Terms

a(0) =2a(1) =3a(2) =5a(3) =7a(4) =211a(5) =223a(6) =229a(7) =241a(8) =271a(9) =283a(10) =311a(11) =313a(12) =317a(13) =331a(14) =337a(15) =347a(16) =353a(17) =359a(18) =367a(19) =373a(20) =379a(21) =383a(22) =389a(23) =397a(24) =523a(25) =541a(26) =547a(27) =571a(28) =719a(29) =743