Composite numbers k such that the digits of the prime factors of k are either 1 or 2.

Terms

a(0) =4a(1) =8a(2) =16a(3) =22a(4) =32a(5) =44a(6) =64a(7) =88a(8) =121a(9) =128a(10) =176a(11) =242a(12) =256a(13) =352a(14) =422a(15) =484a(16) =512a(17) =704a(18) =844a(19) =968a(20) =1024a(21) =1331a(22) =1408a(23) =1688a(24) =1936a(25) =2048a(26) =2321a(27) =2662a(28) =2816a(29) =3376