n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 20 |
5 | 110 |
6 | 612 |
7 | 4970 |
8 | 39600 |
9 | 337680 |
10 | 3298900 |
11 | 39916800 |
12 | 442155168 |
13 | 6151996372 |
14 | 83387930692 |
15 | 1282826630160 |
16 | 19089488332800 |
17 | 355148307803520 |
18 | 5427568925856000 |
19 | 119931789135468100 |
20 | 2432901890279317572 |
21 | 49902667163053013232 |
22 | 1073067539495604750240 |
[1,1,2,6,20,110,612,4970,39600,337680,3298900, 39916800,442155168,6151996372,83387930692, 1282826630160,19089488332800,355148307803520, 5427568925856000,119931789135468100, 2432901890279317572,49902667163053013232, 1073067539495604750240] |