A203685 Vandermonde sequence using x^2 + xy + y^2 applied to (1,2,6,...,n!).

1, 7, 15652, 4466072310336, 257010442859540072735404130304, 12039114411811108434329752218564963041089979745446343475200

Offset

1,2

Comments

See A093883 for a discussion and guide to related sequences.

Links

Table of n, a(n) for n=1..6.

Mathematica

f[j_] := j!; z = 8;
u[n_] := Product[f[j]^2 + f[j] f[k] + f[k]^2,
  {j, 1, k - 1}]
v[n_] := Product[u[n], {k, 2, n}]
Table[v[n], {n, 1, z}]          (* A203685 *)
Table[v[n + 1]/v[n], {n, 1, z}] (* A203686 *)

Crossrefs

Sequence in context: A131676 A344532 A280813 * A134645 A327840 A115997

Adjacent sequences: A203682 A203683 A203684 * A203686 A203687 A203688

Keyword

nonn

Author

Clark Kimberling, Jan 04 2012

Status

approved