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A262497
Minimal nested palindromic primes with seed 11111.
2
11111, 121111121, 71211111217, 3712111112173, 98371211111217389, 129837121111121738921, 3312983712111112173892133, 1063312983712111112173892133601, 12106331298371211111217389213360121, 781210633129837121111121738921336012187
OFFSET
1,1
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.
LINKS
EXAMPLE
As a triangle:
11111
121111121
71211111217
3712111112173
98371211111217389
129837121111121738921
3312983712111112173892133
1063312983712111112173892133601
MATHEMATICA
s0 = "11111"; 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: A038447 A115834 A115810 * A291946 A154807 A076164
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Sep 24 2015
STATUS
approved