n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 15 |
4 | 104 |
5 | 890 |
6 | 8814 |
7 | 100660 |
8 | 1288048 |
9 | 18337680 |
10 | 286674960 |
11 | 4882660464 |
12 | 89880715704 |
13 | 1777384045944 |
14 | 37552294300416 |
15 | 843830334815640 |
16 | 20086549955304384 |
17 | 504750167170162944 |
18 | 13348550475903813120 |
19 | 370499740676381737728 |
20 | 10766442934111876381440 |
[1,1,2,15,104,890,8814,100660,1288048,18337680, 286674960,4882660464,89880715704,1777384045944, 37552294300416,843830334815640,20086549955304384, 504750167170162944,13348550475903813120, 370499740676381737728,10766442934111876381440] |