In binary representation: numbers not occurring in their factorial.

Terms

a(0) =0a(1) =5a(2) =11a(3) =13a(4) =15a(5) =17a(6) =31a(7) =37a(8) =55a(9) =81a(10) =164a(11) =395a(12) =513a(13) =517a(14) =619a(15) =1041a(16) =1287a(17) =1538a(18) =2108a(19) =2116a(20) =2137a(21) =2138a(22) =2282a(23) =2352a(24) =2363a(25) =2432a(26) =2466a(27) =2524a(28) =4278a(29) =4511