n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 4 |
4 | 20 |
5 | 115 |
6 | 715 |
7 | 4683 |
8 | 31824 |
9 | 222300 |
10 | 1586310 |
11 | 11514030 |
12 | 84742320 |
13 | 630946446 |
14 | 4743789260 |
15 | 35965715780 |
16 | 274659794160 |
17 | 2110810059795 |
18 | 16312695488265 |
19 | 126693445737170 |
20 | 988340783454380 |
21 | 7740875273884445 |
22 | 60846920004855985 |
23 | 479854293574853085 |
[1,1,1,4,20,115,715,4683,31824,222300,1586310, 11514030,84742320,630946446,4743789260, 35965715780,274659794160,2110810059795, 16312695488265,126693445737170,988340783454380, 7740875273884445,60846920004855985, 479854293574853085] |