A261818 Minimal nested palindromic primes with seed 1.

1, 313, 93139, 3931393, 11393139311, 1113931393111, 17111393139311171, 331711139313931117133, 3333171113931393111713333, 133331711139313931117133331, 1813333171113931393111713333181, 1951813333171113931393111713333181591

Offset: 1

Author

Clark Kimberling, Sep 17 2015

Keywords

• nonn
• easy
• base

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 have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a symmetric triangle:
......1
.....313
....93139
...3931393
.11393139311
1113931393111
		

Links

• Clark Kimberling, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A261881 (seed 0 with guide to related sequences).

Programs

Mathematica

s = {1}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
(* Peter J. C. Moses, Sep 01 2015 *)