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 A203587 #7 Jan 14 2013 08:35:27
%S A203587 1,7,2793,173302857,3257420083394841,30572436265385693946286383,
%T A203587 213701173947351299768327343802342830897,
%U A203587 1552400172652063971265258662606880393824188151866063025
%N A203587 Vandermonde sequence using x^2 - xy + y^2 applied to (1,3,5,...,2n-1).
%C A203587 See A093883 for a discussion and guide to related sequences.
%t A203587 f[j_] := 2 j - 1; z = 12;
%t A203587 v[n_] := Product[Product[f[j]^2 - f[j] f[k] + f[k]^2,
%t A203587 {j, 1, k - 1}], {k, 2, n}]
%t A203587 Table[v[n], {n, 1, z}] (* A203587 *)
%t A203587 Table[v[n + 1]/v[n], {n, 1, z}] (* A203588 *)
%K A203587 nonn
%O A203587 1,2
%A A203587 _Clark Kimberling_, Jan 04 2012