Numbers of the form 2^k times 1, 3 or 7.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =7a(6) =8a(7) =12a(8) =14a(9) =16a(10) =24a(11) =28a(12) =32a(13) =48a(14) =56a(15) =64a(16) =96a(17) =112a(18) =128a(19) =192a(20) =224a(21) =256a(22) =384a(23) =448a(24) =512a(25) =768a(26) =896a(27) =1024a(28) =1536a(29) =1792