A262649 Minimal nested palindromic base-6 primes with seed 2; see Comments.

2, 525, 1252521, 512525215, 102512525215201, 5110251252521520115, 151102512525215201151, 5515110251252521520115155, 50551511025125252152011515505, 525055151102512525215201151550525, 1152505515110251252521520115155052511

Offset: 1

Author

Clark Kimberling, Oct 27 2015

Keywords

• nonn
• easy
• base

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.

Examples

			a(3) = 1252521 is the least base-6 prime having a(2) = 525 in its middle. Triangular format:
         2
        525
      1252521
     512525215
  102512525215201
5110251252521520115
		

Links

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

Crossrefs

Cf. A261881 (base 10), A262650, A262627.

Programs

Mathematica

s = {2}; 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  (* A262649 *)
Map[FromDigits[ToString[#], base] &, s]  (* A262650 *)
(* Peter J. C. Moses, Sep 01 2015 *)