n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 7 |
4 | 20 |
5 | 54 |
6 | 164 |
7 | 500 |
8 | 1630 |
9 | 5472 |
10 | 19257 |
11 | 70132 |
12 | 265845 |
13 | 1042187 |
14 | 4233556 |
15 | 17747898 |
16 | 76808746 |
17 | 342105748 |
18 | 1567582938 |
19 | 7371055703 |
20 | 35543320641 |
21 | 175391546006 |
22 | 884988267329 |
23 | 4558168670317 |
24 | 23945579145172 |
25 | 128119583103268 |
26 | 697657759802893 |
27 | 3861749505389798 |
[1,1,3,7,20,54,164,500,1630,5472,19257,70132, 265845,1042187,4233556,17747898,76808746, 342105748,1567582938,7371055703,35543320641, 175391546006,884988267329,4558168670317, 23945579145172,128119583103268,697657759802893, 3861749505389798] |