cp's OEIS Frontend

A203679 Vandermonde sequence using x^2 + xy + y^2 applied to (1,2,4,...,2^(n-1)).

%I A203679 #8 Jan 14 2013 08:39:26
%S A203679 1,7,4116,2826802944,33920193794185101312,
%T A203679 110137716338572837381278474323361792,
%U A203679 1523742153535218423780156082312357202968690791891031031808
%N A203679 Vandermonde sequence using x^2 + xy + y^2 applied to (1,2,4,...,2^(n-1)).
%C A203679 See A093883 for a discussion and guide to related sequences.
%t A203679 f[j_] := 2^(j - 1); z = 12;
%t A203679 u[n_] := Product[f[j]^2 + f[j] f[k] + f[k]^2, {j, 1, k - 1}]
%t A203679 v[n_] := Product[u[n], {k, 2, n}]
%t A203679 Table[v[n], {n, 1, z}]          (* A203679 *)
%t A203679 Table[v[n + 1]/v[n], {n, 1, z}] (* A203680 *)
%K A203679 nonn
%O A203679 1,2
%A A203679 _Clark Kimberling_, Jan 04 2012