n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 9 |
4 | 22 |
5 | 115 |
6 | 576 |
7 | 2569 |
8 | 26860 |
9 | 190761 |
10 | 1525420 |
11 | 19634131 |
12 | 210376464 |
13 | 2087806747 |
14 | 24758846490 |
15 | 428700704475 |
16 | 4942787438656 |
17 | 60082160134345 |
18 | 1081105184764044 |
19 | 18121411400219011 |
20 | 271157721708302920 |
[1,1,2,9,22,115,576,2569,26860,190761,1525420, 19634131,210376464,2087806747,24758846490, 428700704475,4942787438656,60082160134345, 1081105184764044,18121411400219011, 271157721708302920] |