n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 3 |
3 | 20 |
4 | 220 |
5 | 3424 |
6 | 69008 |
7 | 1706256 |
8 | 49956240 |
9 | 1689497376 |
10 | 64799254752 |
11 | 2778906776832 |
12 | 131756614920192 |
13 | 6843405231815424 |
14 | 386414606189283072 |
15 | 23567401521343170048 |
16 | 1543994621969805135360 |
17 | 108137637714495023354880 |
18 | 8062825821198926369725440 |
[0,1,3,20,220,3424,69008,1706256,49956240, 1689497376,64799254752,2778906776832, 131756614920192,6843405231815424, 386414606189283072,23567401521343170048, 1543994621969805135360,108137637714495023354880, 8062825821198926369725440] |