A109878 Triangle read by rows: see below.

1, 1, 1, 1, 2, 3, 2, 6, 12, 4, 6, 24, 60, 20, 10, 24, 120, 360, 120, 60, 36, 120, 720, 2520, 840, 420, 252, 168, 720, 5040, 20160, 6720, 3360, 2016, 1344, 960, 5040, 40320, 181440, 60480, 30240, 18144, 12096, 8640, 6480, 40320, 362880, 1814400, 604800

Offset

1,5

Links

Table of n, a(n) for n=1..49.

Example

Consider the formula n! = 1*2*3...*(n-2) + 2*3*4...*(n-1)+ ...+ (n-1)*n*1*2...(n-4) + n*1*2*3*...*(n-3). E.g., 5! = 1*2*3 +2*3*4 +3*4*5 + 4*5*1 + 5*1*2.
Consider the following triangle of partition of n! based on above formula.
1
1 1
1 2 3
2 6 12 4
6 24 60 20 10
24 120 360 120 60 36
...
Sequence contains the triangle by rows.

Mathematica

f[n_] := Times @@@ Sort[Partition[Range[n], n - 2, 1, {-1, -1}]]; Flatten[ Table[ f[n], {n, 2, 10}]] (* Robert G. Wilson v, Jul 13 2005 *)

Crossrefs

Sequence in context: A188881 A143806 A276551 * A354796 A104565 A144456

Adjacent sequences: A109875 A109876 A109877 * A109879 A109880 A109881

Keyword

nonn,tabl

Author

Amarnath Murthy, Jul 10 2005

Extensions

More terms from Robert G. Wilson v, Jul 18 2005

Status

approved