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A261818
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Minimal nested palindromic primes with seed 1.
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3
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1, 313, 93139, 3931393, 11393139311, 1113931393111, 17111393139311171, 331711139313931117133, 3333171113931393111713333, 133331711139313931117133331, 1813333171113931393111713333181, 1951813333171113931393111713333181591
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OFFSET
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1,2
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COMMENTS
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Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.
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LINKS
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EXAMPLE
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As a symmetric triangle:
......1
.....313
....93139
...3931393
.11393139311
1113931393111
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MATHEMATICA
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s = {1}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
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CROSSREFS
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Cf. A261881 (seed 0 with guide to related sequences).
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KEYWORD
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nonn,easy,base
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AUTHOR
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STATUS
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approved
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