|
|
A177939
|
|
Array t(n,m)=(n*m)!/(n + m - 1)! read by antidiagonals.
|
|
1
|
|
|
1, 1, 1, 1, 4, 1, 1, 30, 30, 1, 1, 336, 3024, 336, 1, 1, 5040, 665280, 665280, 5040, 1, 1, 95040, 259459200, 4151347200, 259459200, 95040, 1, 1, 2162160, 158789030400, 60339831552000, 60339831552000, 158789030400, 2162160, 1, 1, 57657600
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,5
|
|
COMMENTS
|
Antidiagonal sums are 1, 2, 6, 62, 3698, 1340642, 4670455682, 120997245489122,
46164597191147635202, 146361193109155192147499522,....
|
|
LINKS
|
|
|
EXAMPLE
|
The array starts in row n=1 as:
1,1,1,1,1,...
1,4,30,336,5040,...
1,30,3024,665280,259459200,...
1,336,665280,4151347200,60339831552000,..
1,5040,259459200,60339831552000,42744736671436800000,..
|
|
MAPLE
|
(n*m)!/(n+m-1)! ;
|
|
MATHEMATICA
|
Clear[t, n]
t[n_, m_] = (n*m)!/(n + m - 1)!;
a = Table[Table[t[n, m], {m, 1, 10}], {n, 1, 10}];
Table[Table[a[[m, n - m + 1]], {m, 1, n}], {n, 1, 10}];
Flatten[%]
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|