Numbers n for which 2n-1, 4n-1, 8n-1, 16n-1 and 32n-1 are primes.

Terms

a(0) =45a(1) =90a(2) =26820a(3) =26925a(4) =30705a(5) =31710a(6) =33375a(7) =63420a(8) =63570a(9) =71805a(10) =83865a(11) =93075a(12) =103185a(13) =127140a(14) =134025a(15) =148050a(16) =170460a(17) =202635a(18) =211035a(19) =223305a(20) =269505a(21) =297225a(22) =303660a(23) =329175a(24) =335625a(25) =362505a(26) =387975a(27) =405270a(28) =405405a(29) =406425