n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 1 |
4 | 4 |
5 | 20 |
6 | 220 |
7 | 2020 |
8 | 26310 |
9 | 332410 |
10 | 5189380 |
11 | 83623310 |
12 | 1551800020 |
13 | 30389755640 |
14 | 659473386920 |
15 | 15190156196820 |
16 | 379169061066320 |
17 | 10036224774532890 |
18 | 283940562045261940 |
19 | 8488369128461080030 |
[1,1,1,4,20,220,2020,26310,332410,5189380, 83623310,1551800020,30389755640,659473386920, 15190156196820,379169061066320,10036224774532890, 283940562045261940,8488369128461080030] |