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 A168257 #12 Sep 08 2022 08:45:48
%S A168257 0,1,9,784
%N A168257 Numbers k with property that 4 + 2*k + 3*k^3 is a square.
%C A168257 4 + 2*k + 3*k^3 = m^2 with k = {0,1,9,784} = {0,1,3,28}^2, and m = 2,3,47,38022.
%o A168257 (Magma)[n: n in [0..10000000]|IsSquare(4+2*n+3*n^3)] // _Vincenzo Librandi_, Dec 16 2010
%K A168257 fini,full,nonn
%O A168257 0,3
%A A168257 _Zak Seidov_, Nov 21 2009