Composite numbers n such that juxtaposition of prime factors of n has length 3.

Terms

a(0) =8a(1) =12a(2) =18a(3) =20a(4) =22a(5) =26a(6) =27a(7) =28a(8) =30a(9) =33a(10) =34a(11) =38a(12) =39a(13) =42a(14) =45a(15) =46a(16) =50a(17) =51a(18) =55a(19) =57a(20) =58a(21) =62a(22) =63a(23) =65a(24) =69a(25) =70a(26) =74a(27) =75a(28) =77a(29) =82