1,1

Every palindrome with an even number of digits is divisible by 11 (in base 4) and therefore is composite (not prime). Hence there is only one palindromic prime with an even number of digits.

Table of n, a(n) for n=1..32.

Eric Weisstein: Palindromic Prime.

Cf. A029972, A117699.

Sequence in context: A249455 A248967 A160169 * A072127 A186976 A160550

Adjacent sequences: A117775 A117776 A117777 * A117779 A117780 A117781

nonn,base

Martin Renner, Apr 15 2006

a(13)-a(32) from Chai Wah Wu, Dec 27 2015

approved