A203766 - OEIS

%I #7 Jan 14 2013 07:52:05

%S 1,2,50,10000,169000000,51409800000000,3714358050000000000000,

%T 8587595811600000000000000000000,

%U 9487238856297219731001600000000000000000000,524056459404241401975165324773422080000000000000000000000

%N Vandermonde sequence using x^2 + y^2 applied to (1,1,2,2,...,floor(n/2)).

%C See A093883 for a discussion and guide to related sequences.

%t f[j_] := Floor[(j + 1)/2]; z = 16;

%t u := Product[f[j]^2 + f[k]^2, {j, 1, k - 1}]

%t v[n_] := Product[u, {k, 2, n}]

%t Table[v[n], {n, 1, z}]          (* A203766 *)

%t Table[v[n + 1]/v[n], {n, 1, z}] (* A203767 *)

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 05 2012