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A261822 Minimal nested palindromic primes with seed 5. 2

%I

%S 5,151,31513,3315133,11331513311,191133151331191,9919113315133119199,

%T 39991911331513311919993,353999191133151331191999353,

%U 13539991911331513311919993531,741353999191133151331191999353147

%N Minimal nested palindromic primes with seed 5.

%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="/A261822/b261822.txt">Table of n, a(n) for n = 1..200</a>

%e As a triangle:

%e .......5

%e ......151

%e .....31513

%e ....3315133

%e ..11331513311

%e 191133151331191

%t s = {5}; 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 May 25 11:29 EDT 2022. Contains 354066 sequences. (Running on oeis4.)