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 A203583 #7 Jan 14 2013 10:15:53
%S A203583 1,7,1092,8278452,5432386430016,486397992095118597312,
%T A203583 8639860170780148341061245616128,
%U A203583 41813829909128704365291419329747443010781184,72587617701933252361662389738534944047336321767596936396800
%N A203583 Vandermonde sequence using x^2 - xy + y^2 applied to (2,3,...,n+1).
%C A203583 See A093883 for a discussion and guide to related sequences.
%t A203583 f[j_] := j + 1; z = 12;
%t A203583 v[n_] := Product[Product[f[j]^2 - f[j] f[k] + f[k]^2,
%t A203583 {j, 1, k - 1}], {k, 2, n}]
%t A203583 Table[v[n], {n, 1, z}] (* A203583 *)
%t A203583 Table[v[n + 1]/v[n], {n, 1, z}] (* A203584 *)
%K A203583 nonn
%O A203583 1,2
%A A203583 _Clark Kimberling_, Jan 04 2012