A262497 Minimal nested palindromic primes with seed 11111.

11111, 121111121, 71211111217, 3712111112173, 98371211111217389, 129837121111121738921, 3312983712111112173892133, 1063312983712111112173892133601, 12106331298371211111217389213360121, 781210633129837121111121738921336012187

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