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A117783 Total number of palindromic primes in base 7 below 7^n. 5
3, 3, 9, 9, 50, 50, 204, 204, 1135, 1135, 6086, 6086, 36018, 36018, 216932, 216932, 1306070, 1306070, 8129138, 8129138, 51773946, 51773946, 326701423, 326701423 (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 7) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits.
LINKS
Eric Weisstein's World of Mathematics, Palindromic Prime.
CROSSREFS
Partial sums of A117784.
Sequence in context: A170832 A232281 A223743 * A121445 A327798 A121074
KEYWORD
nonn,base,more
AUTHOR
Martin Renner, Apr 15 2006
EXTENSIONS
a(9)-a(24) from the data at A117784 added by Amiram Eldar, Mar 21 2021
STATUS
approved

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Last modified July 17 21:15 EDT 2024. Contains 374377 sequences. (Running on oeis4.)