A117772 Total number of palindromic primes in base 2 below 2^n.

0, 1, 3, 3, 5, 5, 8, 8, 11, 11, 18, 18, 30, 30, 53, 53, 93, 93, 187, 187, 329, 329, 600, 600, 1080, 1080, 1936, 1936, 3657, 3657, 6756, 6756, 12328, 12328, 23127, 23127, 43909, 43909, 83377, 83377, 156049, 156049, 295916, 295916, 570396, 570396, 1090772

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 2) and therefore is composite (not prime). Hence there is only one palindromic prime with an even number of digits, namely 11_2 = 3_{10}.

Links

• Martin Raab, Table of n, a(n) for n = 1..66
• Eric Weisstein: Palindromic Prime.

Crossrefs

Cf. A016041, A117697.

Extensions

a(23)-a(40) from Donovan Johnson, Dec 02 2009

Extended to a(66) by Martin Raab, Oct 20 2015