A153229 - cp's OEIS frontend

A153229 a(0) = 0, a(1) = 1, and for n >= 2, a(n) = (n-1) * a(n-2) + (n-2) * a(n-1).

n	a(n)
0	0
1	1
2	0
3	2
4	4
5	20
6	100
7	620
8	4420
9	35900
10	326980
11	3301820
12	36614980
13	442386620
14	5784634180
15	81393657020
16	1226280710980
17	19696509177020
18	335990918918980
19	6066382786809020
20	115578717622022980
21	2317323290554617020
22	48773618881154822980
23	1075227108896452857020

[0, 1, 0, 2, 4, 20, 100, 620, 4420, 35900, 326980, 3301820, 36614980, 442386620, 5784634180, 81393657020, 1226280710980, 19696509177020, 335990918918980, 6066382786809020, 115578717622022980, 2317323290554617020, 48773618881154822980, 1075227108896452857020]

cp's OEIS Frontend

A153229 a(0) = 0, a(1) = 1, and for n >= 2, a(n) = (n-1) * a(n-2) + (n-2) * a(n-1).

Table of values

List of values