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A261824 Minimal nested palindromic primes with seed 7. 2

%I #8 Sep 29 2015 12:50:23

%S 7,373,93739,129373921,3212937392123,34321293739212343,

%T 353432129373921234353,1335343212937392123435331,

%U 1171335343212937392123435331711,1051171335343212937392123435331711501,74105117133534321293739212343533171150147

%N Minimal nested palindromic primes with seed 7.

%C 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.

%H Clark Kimberling, <a href="/A261824/b261824.txt">Table of n, a(n) for n = 1..200</a>

%e As a triangle:

%e ........7

%e .......373

%e ......93739

%e ....129373921

%e ..3212937392123

%e 34321293739212343

%t s = {7}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s

%t (* _Peter J. C. Moses_, Sep 01 2015 *)

%Y Cf. A261881 (seed 0, with guide to related sequences).

%K nonn,easy,base

%O 1,1

%A _Clark Kimberling_, Sep 23 2015

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Last modified September 16 19:55 EDT 2024. Contains 375977 sequences. (Running on oeis4.)