n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 12 |
4 | 60 |
5 | 360 |
6 | 2418 |
7 | 19344 |
8 | 159120 |
9 | 1481040 |
10 | 15334088 |
11 | 184009056 |
12 | 2217441408 |
13 | 31044179712 |
14 | 442487616480 |
15 | 6686252969760 |
16 | 107004539285280 |
17 | 1926081707135040 |
18 | 34683832925921088 |
19 | 693676658518421760 |
20 | 13891399238731734720 |
21 | 292460416142501376000 |
[1,1,3,12,60,360,2418,19344,159120,1481040, 15334088,184009056,2217441408,31044179712, 442487616480,6686252969760,107004539285280, 1926081707135040,34683832925921088, 693676658518421760,13891399238731734720, 292460416142501376000] |