1,1

Every palindrome with an even number of digits is divisible by 11 (in base 6) and therefore is composite (not prime). Hence there is only one palindromic prime with an even number of digits.

Eric Weisstein: Palindromic Prime.

Cf. A029974, A117701.

Sequence in context: A139556 A023896 A128488 this_sequence A075100 A066861 A139063

Adjacent sequences: A117778 A117779 A117780 this_sequence A117782 A117783 A117784

nonn

Martin Renner (martin.renner(AT)gmx.net), Apr 15 2006