A261825 Minimal nested palindromic primes with seed 8.

8, 181, 1218121, 15121812151, 111512181215111, 3311151218121511133, 133111512181215111331, 1113311151218121511133111, 1141113311151218121511133111411, 73114111331115121812151113311141137, 30273114111331115121812151113311141137203

Offset: 1

Author

Clark Kimberling, Sep 23 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 triangle:
.........8
........181
......1218121
....15121812151
..111512181215111
3311151218121511133
		

Links

• Clark Kimberling, Table of n, a(n) for n = 1..200

Crossrefs

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

Programs

Mathematica

s = {8}; 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 *)