A204042 - cp's OEIS frontend

A204042 The number of functions f:{1,2,...,n}->{1,2,...,n} (endofunctions) such that all of the fixed points in f are isolated.

n	a(n)
0	1
1	1
2	2
3	12
4	120
5	1520
6	23160
7	413952
8	8505280
9	197631072
10	5125527360
11	146787894440
12	4601174623584
13	156693888150384
14	5761055539858528
15	227438694372072120
16	9596077520725211520
17	430920897407809702208
18	20520683482765477749120
19	1032920864149903149579336
20	54797532208320308334631840

[1, 1, 2, 12, 120, 1520, 23160, 413952, 8505280, 197631072, 5125527360, 146787894440, 4601174623584, 156693888150384, 5761055539858528, 227438694372072120, 9596077520725211520, 430920897407809702208, 20520683482765477749120, 1032920864149903149579336, 54797532208320308334631840]

cp's OEIS Frontend

A204042 The number of functions f:{1,2,...,n}->{1,2,...,n} (endofunctions) such that all of the fixed points in f are isolated.

Table of values

List of values