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A117780 Total number of palindromic primes in base 5 with n digits. 0
2, 0, 5, 0, 18, 0, 58, 0, 160, 0, 795, 0, 3167, 0, 13519, 0, 60829, 0, 270693, 0, 1177412, 0, 5502114, 0, 25026242, 0, 114884910, 0 (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 5) 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..28.

Eric Weisstein: Palindromic Prime.

CROSSREFS

Cf. A029973, A117700.

Sequence in context: A260330 A094032 A261044 * A155759 A202209 A201730

Adjacent sequences:  A117777 A117778 A117779 * A117781 A117782 A117783

KEYWORD

nonn,base

AUTHOR

Martin Renner, Apr 15 2006

EXTENSIONS

a(11)-a(28) from Chai Wah Wu, Dec 27 2015

STATUS

approved

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Last modified February 19 22:36 EST 2020. Contains 332061 sequences. (Running on oeis4.)