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A117787 Total number of palindromic primes in base 9 below 9^n. 0
4, 4, 17, 17, 81, 81, 499, 499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

Table of n, a(n) for n=1..8.

Eric Weisstein: Palindromic Prime.

CROSSREFS

Cf. A029977, A117703.

Sequence in context: A101407 A294245 A117785 * A113727 A214141 A193961

Adjacent sequences:  A117784 A117785 A117786 * A117788 A117789 A117790

KEYWORD

nonn,base

AUTHOR

Martin Renner, Apr 15 2006

STATUS

approved

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Last modified February 25 20:04 EST 2020. Contains 332258 sequences. (Running on oeis4.)