Numbers n such that n and n+4^k are all primes for k=1,2,3.

Terms

a(0) =3a(1) =7a(2) =37a(3) =43a(4) =67a(5) =163a(6) =757a(7) =823a(8) =967a(9) =1087a(10) =1213a(11) =1303a(12) =1423a(13) =2293a(14) =2377a(15) =3187a(16) =3343a(17) =3847a(18) =5653a(19) =5923a(20) =8677a(21) =8803a(22) =9157a(23) =9277a(24) =9787a(25) =11257a(26) =11617a(27) =11923a(28) =12097a(29) =13693