cp's OEIS Frontend

A262629 Minimal nested base-2 palindromic primes with seed 1.

%I A262629 #9 Oct 17 2015 17:41:06
%S A262629 1,111,11111,1111111,1001111111001,1001001111111001001,
%T A262629 111110010011111110010011111,111111110010011111110010011111111,
%U A262629 100111111110010011111110010011111111001,1011010011111111001001111111001001111111100101101
%N A262629 Minimal nested base-2 palindromic primes with seed 1.
%C A262629 Using only base-2 digits 0 and 1, 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 base-2 palindromic primes with seed s.
%H A262629 Clark Kimberling, <a href="/A262629/b262629.txt">Table of n, a(n) for n = 1..300</a>
%e A262629 a(5) = 1001111111001 = A117697(20) is the least base-2 prime having a(4) = 1111111 = A117697(8) in its middle. Triangular format:
%e A262629              1
%e A262629             111
%e A262629            11111
%e A262629           1111111
%e A262629        1001111111001
%e A262629     1001001111111001001
%e A262629 111110010011111110010011111
%t A262629 s = {1}; base = 2; z = 20; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#, base]], base]] &];
%t A262629 AppendTo[s, FromDigits[IntegerDigits[tmp, base]]], {z}]; s  (* A262629 *)
%t A262629 Map[FromDigits[ToString[#], base] &, s]  (* A262630 *)
%t A262629 (* _Peter J. C. Moses_, Sep 01 2015 *)
%Y A262629 Cf. A261881 (base 10), A262627. Subsequence of A117697 (expect a(1)).
%K A262629 nonn,base
%O A262629 1,2
%A A262629 _Clark Kimberling_, Oct 02 2015