Palindromic prime lengths of factorials: see A035067.

Terms

a(0) =2a(1) =3a(2) =3a(3) =5a(4) =7a(5) =11a(6) =101a(7) =131a(8) =181a(9) =191a(10) =373a(11) =787a(12) =797a(13) =919a(14) =929a(15) =10501a(16) =12721a(17) =13331a(18) =15551a(19) =19391a(20) =30203a(21) =30703a(22) =32423a(23) =37573a(24) =39293a(25) =70207a(26) =71317a(27) =72227a(28) =72727a(29) =76667