1,1

Every palindrome with an even number of digits is divisible by 11 (in base 7) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits.

Eric Weisstein: Palindromic Prime.

Cf. A029975, A117702.

Sequence in context: A128019 A108411 A100066 this_sequence A121445 A121074 A121072

Adjacent sequences: A117780 A117781 A117782 this_sequence A117784 A117785 A117786

nonn

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