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A203681 Vandermonde sequence using x^2 - xy + y^2 applied to (1,2,4,...,2^(n-1)).

%I A203681 #7 Jan 14 2013 08:40:17
%S A203681 1,3,468,66583296,146110606331609088,81505592725670294610465062387712,
%T A203681 187767859619216944607590791201095479470807659625578496,
%U A203681 28804175949984280950704030973074409134657825104658343024583926573114205963127095296
%N A203681 Vandermonde sequence using x^2 - xy + y^2 applied to (1,2,4,...,2^(n-1)).
%C A203681 See A093883 for a discussion and guide to related sequences.
%t A203681 f[j_] := 2^(j - 1); z = 12;
%t A203681 u[n_] := Product[f[j]^2 - f[j] f[k] + f[k]^2,
%t A203681   {j, 1, k - 1}]
%t A203681 v[n_] := Product[u[n], {k, 2, n}]
%t A203681 Table[v[n], {n, 1, z}]          (* A203681 *)
%t A203681 Table[v[n + 1]/v[n], {n, 1, z}] (* A203682 *)
%K A203681 nonn
%O A203681 1,2
%A A203681 _Clark Kimberling_, Jan 04 2012