|
Search: id:A101821
|
|
|
| A101821 |
|
Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n-2} such that |Image(f)|=h, h=1,2,...,n-2; n=3,4,.... |
|
+0
5
|
|
| 2, 3, 42, 4, 180, 600, 5, 620, 5400, 7800, 6, 1890, 36120, 126000, 100800, 7, 5534, 202860, 1428840, 2646000, 1340640, 8, 14280, 1016400, 13053600, 46710720, 53343360, 18627840, 9, 36792, 4702320, 103133520, 642978000, 1380576960
(list; table; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
FORMULA
|
T(n, h) = C(n-2, h)*U(n, h), where U(n, h) is the array in A019538.
|
|
EXAMPLE
|
First rows:
2
3 42
4 180 600
5 620 5400 7800
|
|
CROSSREFS
|
Cf. A019538, A101817, A101819.
Sequence in context: A094714 A042475 A123993 this_sequence A121475 A087571 A126018
Adjacent sequences: A101818 A101819 A101820 this_sequence A101822 A101823 A101824
|
|
KEYWORD
|
nonn,tabl
|
|
AUTHOR
|
Clark Kimberling (ck6(AT)evansville.edu), Dec 17 2004
|
|
|
Search completed in 0.002 seconds
|
