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Search: id:A040025
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| A040025 |
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Number of prime palindromes with 2n+1 digits. |
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+0
2
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| 4, 15, 93, 668, 5172, 42042, 353701, 3036643, 27045226, 239093865, 2158090933
(list; graph; listen)
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OFFSET
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0,1
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LINKS
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Shyam Sunder Gupta, Palindromic Primes up to 10^19.
Shyam Sunder Gupta, Palindromic Primes up to 10^21. [From Shyam Sunder Gupta (guptass(AT)rediffmail.com), Mar 14 2009]
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EXAMPLE
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a(2)=12 because 12th fibonacci number i.e. 144 is the smallest fibonacci number which is a multiple of primorial(2) i.e. 6
a(2)=15 because Number of prime palindromes with 2n+1 i.e. 5 digits is 15. [From Shyam Sunder Gupta (guptass(AT)rediffmail.com), Mar 14 2009]
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CROSSREFS
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Subsequence of A016115, which is the main entry.
Cf. A016115.
Sequence in context: A081011 A008829 A013193 this_sequence A109365 A079128 A081548
Adjacent sequences: A040022 A040023 A040024 this_sequence A040026 A040027 A040028
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KEYWORD
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nonn,hard,base
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AUTHOR
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Patrick De Geest (pdg(AT)worldofnumbers.com)
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EXTENSIONS
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a(10) from Shyam Sunder Gupta (guptass(AT)rediffmail.com), Feb 12 2006
a(11) from Shyam Sunder Gupta (guptass(AT)rediffmail.com), Mar 14 2009
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