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%I #11 Oct 02 2015 13:06:06
%S 111,1311131,113111311,91131113119,9911311131199,12991131113119921,
%T 771299113111311992177,1077129911311131199217701,
%U 11107712991131113119921770111,101110771299113111311992177011101,107101110771299113111311992177011101701
%N Minimal nested palindromic primes with seed 111.
%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 having 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="/A261820/b261820.txt">Table of n, a(n) for n = 1..200</a>
%e As a triangle:
%e 111
%e 1311131
%e 113111311
%e 91131113119
%e 9911311131199
%e 12991131113119921
%e 771299113111311992177
%t s0 = "111"; s = {ToExpression[s0]};Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0],Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
%t (* _Peter J. C. Moses_, Sep 23 2015 *)
%Y Cf. A261881.
%K nonn,base,easy
%O 1,1
%A _Clark Kimberling_, Sep 24 2015
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