A090657 - cp's OEIS frontend

A090657 Triangle read by rows: T(n,k) = number of functions from [1,2,...,n] to [1,2,...,n] such that the image contains exactly k elements (0<=k<=n).

n	a(n)
0	1
1	0
2	1
3	0
4	2
5	2
6	0
7	3
8	18
9	6
10	0
11	4
12	84
13	144
14	24
15	0
16	5
17	300
18	1500
19	1200
20	120
21	0
22	6
23	930
24	10800
25	23400
26	10800
27	720
28	0
29	7
30	2646
31	63210
32	294000
33	352800
34	105840
35	5040
36	0
37	8
38	7112
39	324576
40	2857680
41	7056000
42	5362560
43	1128960
44	40320

[1, 0, 1, 0, 2, 2, 0, 3, 18, 6, 0, 4, 84, 144, 24, 0, 5, 300, 1500, 1200, 120, 0, 6, 930, 10800, 23400, 10800, 720, 0, 7, 2646, 63210, 294000, 352800, 105840, 5040, 0, 8, 7112, 324576, 2857680, 7056000, 5362560, 1128960, 40320]

cp's OEIS Frontend

A090657 Triangle read by rows: T(n,k) = number of functions from [1,2,...,n] to [1,2,...,n] such that the image contains exactly k elements (0<=k<=n).

Table of values

List of values