n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 4 |
4 | 18 |
5 | 112 |
6 | 820 |
7 | 6912 |
8 | 66178 |
9 | 708256 |
10 | 8372754 |
11 | 108306280 |
12 | 1521077404 |
13 | 23041655136 |
14 | 374385141832 |
15 | 6493515450688 |
16 | 119724090206940 |
17 | 2337913445039488 |
18 | 48195668439235612 |
19 | 1045828865817825264 |
20 | 23826258064972682776 |
21 | 568556266922455167040 |
[1,0,1,4,18,112,820,6912,66178,708256,8372754, 108306280,1521077404,23041655136,374385141832, 6493515450688,119724090206940,2337913445039488, 48195668439235612,1045828865817825264, 23826258064972682776,568556266922455167040] |