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A262651 Minimal nested palindromic base-6 primes with seed 3; see Comments. 4
3, 11311, 121131121, 5312113112135, 14531211311213541, 1145312113112135411, 51114531211311213541115, 5511145312113112135411155, 50551114531211311213541115505, 115055111453121131121354111550511, 51150551114531211311213541115505115 (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) = 121131121 is the least base-6 prime having a(2) = 11311 in its middle. Triangular format:

        3

      11311

    121131121

  5312113112135

14531211311213541

MATHEMATICA

s = {3}; 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  (* A262651 *)

Map[FromDigits[ToString[#], base] &, s]  (* A262652 *)

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

CROSSREFS

Cf. A261881 (base 10), A262652, A262627.

Sequence in context: A280300 A171363 A280655 * A309246 A055379 A047777

Adjacent sequences:  A262648 A262649 A262650 * A262652 A262653 A262654

KEYWORD

nonn,easy,base

AUTHOR

Clark Kimberling, Oct 27 2015

STATUS

approved

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Last modified December 1 04:02 EST 2021. Contains 349426 sequences. (Running on oeis4.)