A117787 Total number of palindromic primes in base 9 below 9^n.

4, 4, 17, 17, 81, 81, 499, 499, 3416, 3416, 24255, 24255, 181998, 181998, 1428698, 1428698, 11139859, 11139859, 89160415, 89160415

Offset: 1

Author

Martin Renner, Apr 15 2006

Keywords

• nonn
• base
• more

Comments

Every palindrome with an even number of digits is divisible by 11 (in base 9) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits.

Links

• Eric Weisstein's World of Mathematics, Palindromic Prime.

Crossrefs

Partial sums of A117788.

Cf. A029977, A117703.

Cf. A117772, A117775, A117777, A117779, A117781, A117783, A117785.

Extensions

a(9)-a(20) from the data at A117788 added by Amiram Eldar, Mar 21 2021