This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A262659 #6 Oct 31 2015 15:11:32 %S A262659 0,13031,511303115,3351130311533,333511303115333,1033351130311533301, %T A262659 1051033351130311533301501,35105103335113031153330150153, %U A262659 12135105103335113031153330150153121,12012135105103335113031153330150153121021,331201213510510333511303115333015015312102133 %N A262659 Minimal nested palindromic base-8 primes with seed 0; see Comments. %C A262659 Using only base-8 digits 0,1,2,3,4,5,6,7 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-8 primes with seed s. %H A262659 Clark Kimberling, <a href="/A262659/b262659.txt">Table of n, a(n) for n = 1..300</a> %e A262659 a(3) = 511303115 is the least base-8 prime having a(2) = 13031 in its middle. Triangular format: %e A262659 0 %e A262659 13031 %e A262659 511303115 %e A262659 3351130311533 %e A262659 333511303115333 %e A262659 1033351130311533301 %t A262659 s = {0}; base = 8; z = 20; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#, base]], base]] &]; %t A262659 AppendTo[s, FromDigits[IntegerDigits[tmp, base]]], {z}]; s (* A262659 *) %t A262659 Map[FromDigits[ToString[#], base] &, s] (* A262660 *) %t A262659 (* _Peter J. C. Moses_, Sep 01 2015 *) %Y A262659 Cf. A261881 (base 10), A262660, A262627. %K A262659 nonn,easy,base %O A262659 1,2 %A A262659 _Clark Kimberling_, Oct 27 2015