Numbers k such that A005940(k) is either k itself or its descendant in Doudna-tree, A005940.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =8a(7) =10a(8) =12a(9) =16a(10) =20a(11) =24a(12) =25a(13) =32a(14) =40a(15) =45a(16) =48a(17) =49a(18) =64a(19) =80a(20) =96a(21) =128a(22) =160a(23) =192a(24) =256a(25) =320a(26) =384a(27) =512a(28) =640a(29) =768