Palindromes with exactly 4 prime factors (counted with multiplicity).

Terms

a(0) =88a(1) =232a(2) =414a(3) =424a(4) =444a(5) =484a(6) =525a(7) =585a(8) =636a(9) =666a(10) =676a(11) =686a(12) =808a(13) =858a(14) =868a(15) =999a(16) =1881a(17) =2002a(18) =2332a(19) =2442a(20) =2662a(21) =3003a(22) =3663a(23) =3773a(24) =3993a(25) =4114a(26) =4444a(27) =4774a(28) =5005a(29) =5115