n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 2 |
3 | 6 |
4 | 60 |
5 | 620 |
6 | 7950 |
7 | 129402 |
8 | 2365496 |
9 | 50512968 |
10 | 1208642490 |
11 | 32223422990 |
12 | 947694971652 |
13 | 30435132773916 |
14 | 1061061668979494 |
15 | 39889366397571810 |
16 | 1608910488000292080 |
17 | 69305890226183224592 |
18 | 3175519952912430375666 |
19 | 154216789672147809137046 |
[1,0,2,6,60,620,7950,129402,2365496,50512968, 1208642490,32223422990,947694971652, 30435132773916,1061061668979494,39889366397571810, 1608910488000292080,69305890226183224592, 3175519952912430375666,154216789672147809137046] |