Numbers of the form 2^k times 1, 5 or 7.

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =7a(5) =8a(6) =10a(7) =14a(8) =16a(9) =20a(10) =28a(11) =32a(12) =40a(13) =56a(14) =64a(15) =80a(16) =112a(17) =128a(18) =160a(19) =224a(20) =256a(21) =320a(22) =448a(23) =512a(24) =640a(25) =896a(26) =1024a(27) =1280a(28) =1792a(29) =2048