n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 6 |
4 | 36 |
5 | 200 |
6 | 1230 |
7 | 8652 |
8 | 69272 |
9 | 623520 |
10 | 6235290 |
11 | 68588300 |
12 | 823059732 |
13 | 10699776672 |
14 | 149796873590 |
15 | 2246953104060 |
16 | 35951249665200 |
17 | 611171244308672 |
18 | 11001082397556402 |
19 | 209020565553571980 |
20 | 4180411311071439980 |
21 | 87788637532500240000 |
[0,0,0,6,36,200,1230,8652,69272,623520,6235290, 68588300,823059732,10699776672,149796873590, 2246953104060,35951249665200,611171244308672, 11001082397556402,209020565553571980, 4180411311071439980,87788637532500240000] |