1,1

Every palindrome with an even number of digits is divisible by 11 (in base 5) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits.

Eric Weisstein: Palindromic Prime.

Cf. A029973, A117700.

Sequence in context: A054085 A021443 A045923 this_sequence A091665 A019905 A019732

Adjacent sequences: A117776 A117777 A117778 this_sequence A117780 A117781 A117782

nonn

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