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 A262493 #68 Feb 16 2025 08:33:27
%S A262493 79,131,859,2731,5279,6449,8191,10141,15289,17239,20021,20749,23011,
%T A262493 26209,38039,41081,45319,46411,50909,54419,59281,65651,70981,76519,
%U A262493 80809,86711,92821,99139,126491,128311,135721,159199,167441,175891,200201,209431,221261,230959
%N A262493 Centered 13-gonal (or tridecagonal) primes.
%C A262493 Primes of the form (13*k^2 - 13*k + 2)/2.
%H A262493 Harvey P. Dale, <a href="/A262493/b262493.txt">Table of n, a(n) for n = 1..1000</a>
%H A262493 OEIS Wiki, <a href="https://oeis.org/wiki/Figurate_numbers">Figurate numbers</a>
%H A262493 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPolygonalNumber.html">Centered Polygonal Number</a>
%H A262493 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeNumber.html">Prime Number</a>
%t A262493 Select[Table[(13k^2-13k+2)/2,{k,200}],PrimeQ] (* _Harvey P. Dale_, Jun 16 2023 *)
%o A262493 (PARI) for(n=1, 1e3, if(isprime(k=(13*n^2-13*n+2)/2), print1(k,", "))) \\ _Altug Alkan_, Nov 26 2015
%Y A262493 Cf. A069126, A000040.
%K A262493 nonn
%O A262493 1,1
%A A262493 _Ilya Gutkovskiy_, Nov 26 2015