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A262653 Minimal nested palindromic base-6 primes with seed 4; see Comments. 3
4, 141, 11411, 5114115, 551141155, 1455114115541, 1111455114115541111, 55111145511411554111155, 1021551111455114115541111551201, 12102155111145511411554111155120121, 531210215511114551141155411115512012135, 101531210215511114551141155411115512012135101 (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) = 11411 is the least base-6 prime having a(2) = 141 in its middle. Triangular format:

      4

     141

    11411

   5114115

  551141155

1455114115541

MATHEMATICA

s = {4}; 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  (* A262653 *)

Map[FromDigits[ToString[#], base] &, s]  (* A262654 *)

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

CROSSREFS

Cf. A261881 (base 10), A262654, A262627.

Sequence in context: A215606 A119038 A048432 * A299061 A299722 A210831

Adjacent sequences:  A262650 A262651 A262652 * A262654 A262655 A262656

KEYWORD

nonn,easy,base

AUTHOR

Clark Kimberling, Oct 27 2015

STATUS

approved

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Last modified January 24 04:35 EST 2020. Contains 331183 sequences. (Running on oeis4.)