OFFSET
1,2
COMMENTS
See A093883 for a discussion and guide to related sequences.
FORMULA
a(n) ~ 2^(3*n^2/2 - 3*n/2 - 3/8) * n^(n*(n-1)) / exp((6 - Pi)*n^2/4 - n + Pi/48). - Vaclav Kotesovec, Sep 08 2023
MATHEMATICA
f[j_] := 2 j - 1; z = 12;
v[n_] := Product[Product[f[j]^2 + f[k]^2, {j, 1, k - 1}], {k, 2, n}]
Table[v[n], {n, 1, z}] (* A203589 *)
Table[v[n + 1]/v[n], {n, 1, z}] (* A203590 *)
Table[Product[(2*k - 1)^2 + (2*j - 1)^2, {k, 1, n}, {j, 1, k-1}], {n, 1, 10}] (* Vaclav Kotesovec, Sep 08 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 04 2012
STATUS
approved