Divisible only by primes congruent to 7 mod 8.

Terms

a(0) =1a(1) =7a(2) =23a(3) =31a(4) =47a(5) =49a(6) =71a(7) =79a(8) =103a(9) =127a(10) =151a(11) =161a(12) =167a(13) =191a(14) =199a(15) =217a(16) =223a(17) =239a(18) =263a(19) =271a(20) =311a(21) =329a(22) =343a(23) =359a(24) =367a(25) =383a(26) =431a(27) =439a(28) =463a(29) =479