|
%I #8 Oct 26 2015 22:24:45
%S 1,111,1111111,14111111141,111411111114111,103111411111114111301,
%T 5510311141111111411130155,10551031114111111141113015501,
%U 501055103111411111114111301550105,102501055103111411111114111301550105201,5110250105510311141111111411130155010520115
%N Minimal nested palindromic base-6 primes with seed 1; 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="/A262647/b262647.txt">Table of n, a(n) for n = 1..300</a>
%e a(3) = 1111111 is the least base-6 prime having a(2) = 111 in its middle. Triangular format:
%e 1
%e 111
%e 1111111
%e 14111111141
%e 111411111114111
%e 103111411111114111301
%t s = {1}; 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 (* A262647 *)
%t Map[FromDigits[ToString[#], base] &, s] (* A262648 *)
%t (* _Peter J. C. Moses_, Sep 01 2015 *)
%Y Cf. A261881 (base 10), A262648, A262627.
%K nonn,base
%O 1,2
%A _Clark Kimberling_, Oct 25 2015
|
