Nonprimes whose average of proper divisors is an integer.

Terms

a(0) =6a(1) =9a(2) =15a(3) =25a(4) =30a(5) =33a(6) =44a(7) =49a(8) =51a(9) =69a(10) =81a(11) =87a(12) =91a(13) =114a(14) =117a(15) =120a(16) =121a(17) =123a(18) =124a(19) =133a(20) =135a(21) =141a(22) =159a(23) =164a(24) =169a(25) =170a(26) =177a(27) =182a(28) =207a(29) =213