A117784 Total number of palindromic primes in base 7 with n digits.

3, 0, 6, 0, 41, 0, 154, 0, 931, 0, 4951, 0, 29932, 0, 180914, 0, 1089138, 0, 6823068, 0, 43644808, 0, 274927477, 0

Offset: 1

Author

Martin Renner, Apr 15 2006

Keywords

• nonn
• base

Comments

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.

Links

• Eric Weisstein: Palindromic Prime.

Crossrefs

Cf. A029975, A117702.

Extensions

a(9)-a(24) from Chai Wah Wu, Dec 26 2015