A101817 - cp's OEIS frontend

A101817 Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n} such that |Image(f)|=h; h=1,2,...,n, n=1,2,3,... . Essentially A090657, but without zeros.

n	a(n)
1	1
2	2
3	2
4	3
5	18
6	6
7	4
8	84
9	144
10	24
11	5
12	300
13	1500
14	1200
15	120
16	6
17	930
18	10800
19	23400
20	10800
21	720
22	7
23	2646
24	63210
25	294000
26	352800
27	105840
28	5040
29	8
30	7112
31	324576
32	2857680
33	7056000
34	5362560
35	1128960
36	40320
37	9
38	18360
39	1524600
40	23496480
41	105099120

[1, 2, 2, 3, 18, 6, 4, 84, 144, 24, 5, 300, 1500, 1200, 120, 6, 930, 10800, 23400, 10800, 720, 7, 2646, 63210, 294000, 352800, 105840, 5040, 8, 7112, 324576, 2857680, 7056000, 5362560, 1128960, 40320, 9, 18360, 1524600, 23496480, 105099120]

cp's OEIS Frontend

A101817 Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n} such that |Image(f)|=h; h=1,2,...,n, n=1,2,3,... . Essentially A090657, but without zeros.

Table of values

List of values