Numbers with an even number of distinct prime factors.

Terms

a(0) =1a(1) =6a(2) =10a(3) =12a(4) =14a(5) =15a(6) =18a(7) =20a(8) =21a(9) =22a(10) =24a(11) =26a(12) =28a(13) =33a(14) =34a(15) =35a(16) =36a(17) =38a(18) =39a(19) =40a(20) =44a(21) =45a(22) =46a(23) =48a(24) =50a(25) =51a(26) =52a(27) =54a(28) =55a(29) =56