Numbers n such that 2n-1, 4n-1, 8n-1, 16n-1, 32n-1 and 64n-1 are primes.

Terms

a(0) =45a(1) =31710a(2) =63570a(3) =202635a(4) =405405a(5) =534600a(6) =561330a(7) =589305a(8) =666945a(9) =799350a(10) =903045a(11) =979125a(12) =1082115a(13) =1122660a(14) =1164735a(15) =1303035a(16) =1424475a(17) =1620645a(18) =1669995a(19) =1892100a(20) =1981020a(21) =2044440a(22) =2164230a(23) =2222415a(24) =2329470a(25) =2332125a(26) =2447445a(27) =2448855