A203766 Vandermonde sequence using x^2 + y^2 applied to (1,1,2,2,...,floor(n/2)).

1, 2, 50, 10000, 169000000, 51409800000000, 3714358050000000000000, 8587595811600000000000000000000, 9487238856297219731001600000000000000000000, 524056459404241401975165324773422080000000000000000000000

Offset: 1

Author

Clark Kimberling, Jan 05 2012

Keywords

• nonn

Comments

See A093883 for a discussion and guide to related sequences.

Programs

Mathematica

f[j_] := Floor[(j + 1)/2]; z = 16;
u := Product[f[j]^2 + f[k]^2, {j, 1, k - 1}]
v[n_] := Product[u, {k, 2, n}]
Table[v[n], {n, 1, z}]          (* A203766 *)
Table[v[n + 1]/v[n], {n, 1, z}] (* A203767 *)