Scan decimal expansion of Mersenne primes (A000668), recording all primes seen.

Terms

a(0) =3a(1) =7a(2) =31a(3) =2a(4) =127a(5) =19a(6) =191a(7) =8191a(8) =13a(9) =71a(10) =107a(11) =131a(12) =131071a(13) =5a(14) =524287a(15) =47a(16) =83a(17) =647a(18) =2147483647a(19) =23a(20) =43a(21) =5843a(22) =13693a(23) =4300921a(24) =5843009a(25) =584300921a(26) =2305843009a(27) =5843009213a(28) =30584300921a(29) =43009213693