Union of all numbers {p, q} where p and q are both primes or powers of primes and q = p+2.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =7a(6) =9a(7) =11a(8) =13a(9) =17a(10) =19a(11) =23a(12) =25a(13) =27a(14) =29a(15) =31a(16) =41a(17) =43a(18) =47a(19) =49a(20) =59a(21) =61a(22) =71a(23) =73a(24) =79a(25) =81a(26) =83a(27) =101a(28) =103a(29) =107