A262531 Minimal nested palindromic primes with seed 000.

1300031, 10130003101, 171013000310171, 91710130003101719, 3917101300031017193, 16391710130003101719361, 10116391710130003101719361101, 191011639171013000310171936110191, 91910116391710130003101719361101919, 119191011639171013000310171936110191911

Offset

2,1

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 having a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s. (For A261819, the seed is not an integer, so that the offset is 2.)

Links

Clark Kimberling, Table of n, a(n) for n = 2..200

Example

As a triangle:
          000
        1300031
      10130003101
    171013000310171
   91710130003101719
  3917101300031017193
16391710130003101719361

Mathematica

s0 = "000"; s = {ToExpression[s0]}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0], Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
(* Peter J. C. Moses, Sep 23 2015 *)

Crossrefs

Cf. A261881.

Sequence in context: A185776 A345083 A345084 * A250830 A258535 A258528

Adjacent sequences: A262528 A262529 A262530 * A262532 A262533 A262534

Keyword

nonn,base,easy

Author

Clark Kimberling, Sep 24 2015

Status

approved