A144085 - cp's OEIS frontend

A144085 a(n) is the number of partial bijections (or subpermutations) of an n-element set without fixed points (also called partial derangements).

n	a(n)
0	1
1	1
2	4
3	18
4	108
5	780
6	6600
7	63840
8	693840
9	8361360
10	110557440
11	1590351840
12	24713156160
13	412393101120
14	7352537512320
15	139443752448000
16	2802408959750400
17	59479486120454400
18	1329239028813696000
19	31194214921732262400
20	766888191387539020800
21	19707387644116280908800
22	528327710066244459571200

[1, 1, 4, 18, 108, 780, 6600, 63840, 693840, 8361360, 110557440, 1590351840, 24713156160, 412393101120, 7352537512320, 139443752448000, 2802408959750400, 59479486120454400, 1329239028813696000, 31194214921732262400, 766888191387539020800, 19707387644116280908800, 528327710066244459571200]

cp's OEIS Frontend

A144085 a(n) is the number of partial bijections (or subpermutations) of an n-element set without fixed points (also called partial derangements).

Table of values

List of values