A262645 - OEIS

%I #10 Oct 26 2015 22:24:30

%S 0,101,5110115,13511011531,1135110115311,111351101153111,

%T 152111351101153111251,5215211135110115311125125,

%U 1025215211135110115311125125201,1431025215211135110115311125125201341,1111431025215211135110115311125125201341111

%N Minimal nested palindromic base-6 primes with seed 0; see Comments.

%C Using only base-6 digits 0,1,2,3,4,5, 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 base-6 primes with seed s.

%H Clark Kimberling, <a href="/A262645/b262645.txt">Table of n, a(n) for n = 1..300</a>

%e a(3) = 5110115 is the least base-6 prime having a(2) = 101 in its middle.

%e Triangular format:

%e          0

%e         101

%e       5110115

%e     13511011531

%e    1135110115311

%e   111351101153111

%t s = {0}; base = 6; z = 20; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#, base]], base]] &];

%t AppendTo[s, FromDigits[IntegerDigits[tmp, base]]], {z}]; s  (* A262645 *)

%t Map[FromDigits[ToString[#], base] &, s]  (* A262646 *)

%t (* _Peter J. C. Moses_, Sep 01 2015 *)

%Y Cf. A261881 (base 10), A262646, A262627.

%K nonn,base

%O 1,2

%A _Clark Kimberling_, Oct 24 2015