|
|
A084980
|
|
Triangle of (multi)factorials: n-th row is (n+1)!!... {n "!"s}, (n+1)!... {n-1 "!"s}, ..., (n+1)!.
|
|
2
|
|
|
2, 3, 6, 4, 8, 24, 5, 10, 15, 120, 6, 12, 18, 48, 720, 7, 14, 21, 28, 105, 5040, 8, 16, 24, 32, 80, 384, 40320, 9, 18, 27, 36, 45, 162, 945, 362880, 10, 20, 30, 40, 50, 120, 280, 3840, 3628800, 11, 22, 33, 44, 55, 66, 231, 880, 10395, 39916800, 12, 24, 36, 48, 60, 72, 168
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
Triangle begins
Row 1: 2! = 2
Row 2: 3!! = 3*1 = 3, 3! = 3*2*1 = 6
Row 3: 4!!! = 4*1 = 4, 4!! = 4*2 = 8, 4! = 4*3*2*1 = 24,
Row 4: 5!!!! = 5*1 = 5, 5!!! = 5*2 = 10, 5!! = 5*3 = 15, 5! = 5*4*3*2*1 = 120,
...
|
|
MATHEMATICA
|
Flatten[Table[Times @@ Range[n, 1, -i], {n, 12}, {i, n - 1, 1, -1}]] (* Ivan Neretin, May 09 2015 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|