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 A264823 #12 Feb 16 2025 08:33:27
%S A264823 17,97,241,337,449,577,881,1249,3041,3361,3697,4049,4801,6961,7937,
%T A264823 9521,10657,13121,14449,15137,16561,18049,23761,25537,26449,31249,
%U A264823 32257,37537,39761,40897,46817,48049,49297,54449,58481,64081,65521,66977,68449,77617,79201
%N A264823 Centered 16-gonal (or hexadecagonal) primes.
%C A264823 Primes of the form 8*k^2 - 8*k + 1.
%H A264823 OEIS Wiki, <a href="https://oeis.org/wiki/Figurate_numbers">Figurate numbers</a>
%H A264823 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPolygonalNumber.html">Centered Polygonal Number</a>
%H A264823 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeNumber.html">Prime Number</a>
%t A264823 Select[Table[8k^2-8k+1,{k,0,100}],PrimeQ] (* _Harvey P. Dale_, Mar 08 2023 *)
%o A264823 (PARI) for(n=1, 1e3, if(isprime(k=8*n^2-8*n+1), print1(k,", "))) \\ _Altug Alkan_, Nov 26 2015
%Y A264823 Cf. A069129, A000040.
%K A264823 nonn
%O A264823 1,1
%A A264823 _Ilya Gutkovskiy_, Nov 26 2015