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Minimal nested palindromic primes with seed 000.
2

%I #11 Oct 02 2015 13:09:08

%S 1300031,10130003101,171013000310171,91710130003101719,

%T 3917101300031017193,16391710130003101719361,

%U 10116391710130003101719361101,191011639171013000310171936110191,91910116391710130003101719361101919,119191011639171013000310171936110191911

%N Minimal nested palindromic primes with seed 000.

%C 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.)

%H Clark Kimberling, <a href="/A262531/b262531.txt">Table of n, a(n) for n = 2..200</a>

%e As a triangle:

%e 000

%e 1300031

%e 10130003101

%e 171013000310171

%e 91710130003101719

%e 3917101300031017193

%e 16391710130003101719361

%t 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}]

%t (* _Peter J. C. Moses_, Sep 23 2015 *)

%Y Cf. A261881.

%K nonn,base,easy

%O 2,1

%A _Clark Kimberling_, Sep 24 2015