A203755 Vandermonde sequence using x^4 + y^4 applied to (0,1,1,2,2,...,floor(n/2)).

1, 1, 2, 9248, 1368408064, 7012482928301113344, 5821608871192502942968054284288, 827078717211493220641742410981240687143117914112, 60161773220249337113595772781004931116549061984924929733289475833856

Offset

1,3

Comments

See A093883 for a discussion and guide to related sequences.

Links

Table of n, a(n) for n=1..9.

Mathematica

f[j_] := Floor[j/2]; z = 16;
u := Product[f[j]^4 + f[k]^4, {j, 1, k - 1}]
v[n_] := Product[u, {k, 2, n}]
Table[v[n], {n, 1, z}]        (* A203755 *)
Table[v[n + 1]/v[n], {n, 1, z}]  (* A203756 *)
Table[Sqrt[v[n + 1]/v[n]], {n, 1, z}]
Table[Sqrt[v[2 n]/v[2 n - 1]], {n, 1, z}]  (* A203757 *)
Table[Sqrt[v[2 n + 1]/(2 v[2 n])],
  {n, 1, z}]  (* A203758 *)
%/%%   (* A000290 *)

Crossrefs

Sequence in context: A104904 A272247 A167748 * A285692 A340546 A343700

Adjacent sequences: A203752 A203753 A203754 * A203756 A203757 A203758

Keyword

nonn

Author

Clark Kimberling, Jan 05 2012

Status

approved