Palindromic nonprime numbers.

Terms

a(0) =1a(1) =4a(2) =6a(3) =8a(4) =9a(5) =22a(6) =33a(7) =44a(8) =55a(9) =66a(10) =77a(11) =88a(12) =99a(13) =111a(14) =121a(15) =141a(16) =161a(17) =171a(18) =202a(19) =212a(20) =222a(21) =232a(22) =242a(23) =252a(24) =262a(25) =272a(26) =282a(27) =292a(28) =303a(29) =323