A261821 Minimal nested palindromic primes with seed 4.

4, 11411, 1114111, 18111411181, 741811141118147, 1674181114111814761, 90167418111411181476109, 3901674181114111814761093, 14390167418111411181476109341, 9143901674181114111814761093419, 75914390167418111411181476109341957

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:
.........4
.......11411
......1114111
....18111411181
..741811141118147
1674181114111814761
		

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 = {4}; 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 *)