Palindromic odd composite numbers with an odd number of prime factors (counted with multiplicity).

Terms

a(0) =99a(1) =171a(2) =333a(3) =343a(4) =363a(5) =555a(6) =575a(7) =595a(8) =747a(9) =777a(10) =909a(11) =969a(12) =1001a(13) =1221a(14) =1331a(15) =1551a(16) =1771a(17) =3333a(18) =3553a(19) =5335a(20) =5445a(21) =5555a(22) =5665a(23) =5775a(24) =5885a(25) =5995a(26) =7337a(27) =7557a(28) =7667a(29) =7777