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A262655 Minimal nested palindromic base-6 primes with seed 5; see Comments. 3
5, 151, 11511, 5115115, 13511511531, 5135115115315, 15513511511531551, 1155135115115315511, 14115513511511531551141, 131411551351151153155114131, 51314115513511511531551141315, 11551314115513511511531551141315511, 11511551314115513511511531551141315511511 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Using only base-6 digits 0,1,2,3,4,5, 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 base-6 primes with seed s.

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..300

EXAMPLE

a(3) = 11511 is the least base-6 prime having a(2) = 151 in its middle.

Triangular format:

        5

       151

      11511

     5115115

   13511511531

  5135115115315

MATHEMATICA

s = {5}; base = 6; z = 20; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#, base]], base]] &];

AppendTo[s, FromDigits[IntegerDigits[tmp, base]]], {z}]; s  (* A262655 *)

Map[FromDigits[ToString[#], base] &, s]  (* A262656 *)

(* Peter J. C. Moses, Sep 01 2015 *)

CROSSREFS

Cf. A261881 (base 10), A262656, A262627.

Sequence in context: A258486 A082623 A332115 * A075598 A214691 A261822

Adjacent sequences:  A262652 A262653 A262654 * A262656 A262657 A262658

KEYWORD

nonn,easy,base

AUTHOR

Clark Kimberling, Oct 27 2015

STATUS

approved

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Last modified May 22 09:12 EDT 2022. Contains 353941 sequences. (Running on oeis4.)