n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 4 |
4 | 25 |
5 | 156 |
6 | 1561 |
7 | 15968 |
8 | 205521 |
9 | 2996416 |
10 | 48245521 |
11 | 891169632 |
12 | 17701061929 |
13 | 390008578688 |
14 | 9273243108585 |
15 | 237666643184896 |
16 | 6557636429111329 |
17 | 192526245072832512 |
18 | 6029011794295629217 |
19 | 199832740470058237952 |
20 | 7000664928137597341881 |
[1,1,1,4,25,156,1561,15968,205521,2996416, 48245521,891169632,17701061929,390008578688, 9273243108585,237666643184896,6557636429111329, 192526245072832512,6029011794295629217, 199832740470058237952,7000664928137597341881] |