A261826 Minimal nested palindromic primes with seed 9.

9, 191, 71917, 147191741, 3914719174193, 139147191741931, 7213914719174193127, 33721391471917419312733, 9337213914719174193127339, 1719337213914719174193127339171, 11171933721391471917419312733917111, 1111719337213914719174193127339171111

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:
.......9
......191
.....71917
...147191741
.3914719174193
139147191741931
		

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 = {9}; 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 *)