1,3
Every palindrome with an even number of digits is divisible by 11 (in base 3) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits.
Table of n, a(n) for n=1..14.
Eric Weisstein: Palindromic Prime.
Cf. A029971, A117698.
Sequence in context: A219627 A131942 A200905 * A021301 A016652 A008867
Adjacent sequences: A117772 A117773 A117774 * A117776 A117777 A117778
nonn,base
Martin Renner, Apr 15 2006
approved