n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 21 |
4 | 124 |
5 | 781 |
6 | 5120 |
7 | 34474 |
8 | 236492 |
9 | 1644222 |
10 | 11543644 |
11 | 81623504 |
12 | 580104672 |
13 | 4137414963 |
14 | 29574658416 |
15 | 211639869236 |
16 | 1514729242092 |
17 | 10832683182538 |
18 | 77342204972120 |
19 | 550791674067623 |
20 | 3908735530965604 |
21 | 27612614422978557 |
22 | 193943797650498016 |
[1,1,4,21,124,781,5120,34474,236492,1644222, 11543644,81623504,580104672,4137414963, 29574658416,211639869236,1514729242092, 10832683182538,77342204972120,550791674067623, 3908735530965604,27612614422978557, 193943797650498016] |