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 A261818 Minimal nested palindromic primes with seed 1. 3
 1, 313, 93139, 3931393, 11393139311, 1113931393111, 17111393139311171, 331711139313931117133, 3333171113931393111713333, 133331711139313931117133331, 1813333171113931393111713333181, 1951813333171113931393111713333181591 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 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. LINKS Clark Kimberling, Table of n, a(n) for n = 1..100 EXAMPLE As a symmetric triangle: ......1 .....313 ....93139 ...3931393 .11393139311 1113931393111 MATHEMATICA s = {1}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s (* Peter J. C. Moses, Sep 01 2015 *) CROSSREFS Cf. A261881 (seed 0 with guide to related sequences). Sequence in context: A332131 A287294 A255388 * A083997 A164772 A068650 Adjacent sequences: A261815 A261816 A261817 * A261819 A261820 A261821 KEYWORD nonn,easy,base AUTHOR Clark Kimberling, Sep 17 2015 STATUS approved

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Last modified December 5 12:42 EST 2022. Contains 358586 sequences. (Running on oeis4.)