n | a(n) |
---|---|
1 | 1 |
2 | 2 |
3 | 6 |
4 | 18 |
5 | 80 |
6 | 370 |
7 | 2352 |
8 | 14434 |
9 | 117504 |
10 | 902178 |
11 | 8983040 |
12 | 82751218 |
13 | 973639680 |
14 | 10464269842 |
15 | 142066391040 |
16 | 1744984627650 |
17 | 26849099841536 |
18 | 371007716472130 |
19 | 6380079728689152 |
20 | 97957282718195410 |
21 | 1861853565120675840 |
22 | 31444800527373324210 |
23 | 654585210392831590400 |
[1,2,6,18,80,370,2352,14434,117504,902178,8983040, 82751218,973639680,10464269842,142066391040, 1744984627650,26849099841536,371007716472130, 6380079728689152,97957282718195410, 1861853565120675840,31444800527373324210, 654585210392831590400] |