A261824 Minimal nested palindromic primes with seed 7.

7, 373, 93739, 129373921, 3212937392123, 34321293739212343, 353432129373921234353, 1335343212937392123435331, 1171335343212937392123435331711, 1051171335343212937392123435331711501, 74105117133534321293739212343533171150147

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:
........7
.......373
......93739
....129373921
..3212937392123
34321293739212343
		

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 = {7}; 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 *)