|
|
A323496
|
|
a(n) = Product_{k=1..n} (binomial(k-1,3) + binomial(n-k,3)).
|
|
6
|
|
|
1, 0, 0, 0, 0, 0, 1600, 1280000, 1225000000, 1487467520000, 2342962705305600, 4757234928058368000, 12302981968140864000000, 39976163552160000000000000, 161025498138224463853824000000, 794000312545927932130993635328000, 4737527580526919896601692054005760000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,7
|
|
LINKS
|
|
|
FORMULA
|
a(n) ~ exp(2*Pi*(n-3)/3^(3/2) - 2*n - 3) * n^(3*n) / 6^n.
|
|
MATHEMATICA
|
Table[Product[Binomial[k-1, 3] + Binomial[n-k, 3], {k, 1, n}], {n, 0, 20}]
|
|
PROG
|
(PARI) a(n) = prod(k=1, n, binomial(k-1, 3) + binomial(n-k, 3)); \\ Michel Marcus, Jan 17 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|