A259869 - cp's OEIS frontend

A259869 a(0) = -1; for n > 0, number of indecomposable derangements, i.e., no fixed points, and not fixing [1..j] for any 1 <= j < n.

n	a(n)
0	-1
1	0
2	1
3	2
4	8
5	40
6	244
7	1736
8	14084
9	128176
10	1292788
11	14313272
12	172603124
13	2252192608
14	31620422980
15	475350915656
16	7618759828388
17	129697180826512
18	2337145267316500
19	44446207287450968
20	889595868295057364
21	18693361200724345024
22	411475140936880082020

[-1, 0, 1, 2, 8, 40, 244, 1736, 14084, 128176, 1292788, 14313272, 172603124, 2252192608, 31620422980, 475350915656, 7618759828388, 129697180826512, 2337145267316500, 44446207287450968, 889595868295057364, 18693361200724345024, 411475140936880082020]

cp's OEIS Frontend

A259869 a(0) = -1; for n > 0, number of indecomposable derangements, i.e., no fixed points, and not fixing [1..j] for any 1 <= j < n.

Table of values

List of values