A002720 - cp's OEIS frontend

A002720 Number of partial permutations of an n-set; number of n X n binary matrices with at most one 1 in each row and column.

n	a(n)
0	1
1	2
2	7
3	34
4	209
5	1546
6	13327
7	130922
8	1441729
9	17572114
10	234662231
11	3405357682
12	53334454417
13	896324308634
14	16083557845279
15	306827170866106
16	6199668952527617
17	132240988644215842
18	2968971263911288999
19	69974827707903049154
20	1727194482044146637521
21	44552237162692939114282

[1, 2, 7, 34, 209, 1546, 13327, 130922, 1441729, 17572114, 234662231, 3405357682, 53334454417, 896324308634, 16083557845279, 306827170866106, 6199668952527617, 132240988644215842, 2968971263911288999, 69974827707903049154, 1727194482044146637521, 44552237162692939114282]

cp's OEIS Frontend

A002720 Number of partial permutations of an n-set; number of n X n binary matrices with at most one 1 in each row and column.

Table of values

List of values