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A117772
Total number of palindromic primes in base 2 below 2^n.
7
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
1,3
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
Eric Weisstein: Palindromic Prime.
CROSSREFS
Sequence in context: A308415 A063281 A362059 * A026924 A240313 A275369
KEYWORD
nonn,base
AUTHOR
Martin Renner, Apr 15 2006
EXTENSIONS
a(23)-a(40) from Donovan Johnson, Dec 02 2009
Extended to a(66) by Martin Raab, Oct 20 2015
STATUS
approved