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A262498
Minimal nested palindromic primes with seed 1111111.
2
1111111, 14111111141, 131411111114131, 91314111111141319, 389131411111114131983, 7238913141111111413198327, 16723891314111111141319832761, 381672389131411111114131983276183, 1638167238913141111111413198327618361, 1191638167238913141111111413198327618361911
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:
1111111
14111111141
131411111114131
91314111111141319
389131411111114131983
7238913141111111413198327
16723891314111111141319832761
381672389131411111114131983276183
MATHEMATICA
s0 = "1111111"; 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: A359347 A035613 A038449 * A257937 A205735 A205916
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Sep 24 2015
STATUS
approved