n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 9 |
3 | 44 |
4 | 250 |
5 | 1418 |
6 | 8567 |
7 | 51635 |
8 | 321039 |
9 | 1996724 |
10 | 12628528 |
11 | 80011583 |
12 | 511889348 |
13 | 3282172599 |
14 | 21172582733 |
15 | 136879748346 |
16 | 888481523846 |
17 | 5778565689270 |
18 | 37689416642042 |
19 | 246245960185175 |
20 | 1612234572834084 |
[1,2,9,44,250,1418,8567,51635,321039,1996724, 12628528,80011583,511889348,3282172599, 21172582733,136879748346,888481523846, 5778565689270,37689416642042,246245960185175, 1612234572834084] |