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A262497 Minimal nested palindromic primes with seed 11111. 2
11111, 121111121, 71211111217, 3712111112173, 98371211111217389, 129837121111121738921, 3312983712111112173892133, 1063312983712111112173892133601, 12106331298371211111217389213360121, 781210633129837121111121738921336012187 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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 having 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..200

EXAMPLE

As a triangle:

             11111

           121111121

          71211111217

         3712111112173

       98371211111217389

     129837121111121738921

   3312983712111112173892133

1063312983712111112173892133601

MATHEMATICA

s0 = "11111"; 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}]

(* Peter J. C. Moses, Sep 23 2015 *)

CROSSREFS

Cf. A261881.

Sequence in context: A038447 A115834 A115810 * A291946 A154807 A076164

Adjacent sequences:  A262494 A262495 A262496 * A262498 A262499 A262500

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Sep 24 2015

STATUS

approved

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Last modified October 27 05:20 EDT 2021. Contains 348271 sequences. (Running on oeis4.)