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: A007385 A022899 A081978 this_sequence A111074 A007384 A077574

Adjacent sequences: A117781 A117782 A117783 this_sequence A117785 A117786 A117787

nonn

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