n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 4 |
4 | 19 |
5 | 116 |
6 | 835 |
7 | 6890 |
8 | 63826 |
9 | 654552 |
10 | 7354893 |
11 | 89830770 |
12 | 1184915556 |
13 | 16788863356 |
14 | 254342837905 |
15 | 4103256660048 |
16 | 70241858430220 |
17 | 1271839899568064 |
18 | 24287699718766932 |
19 | 487891841580468294 |
20 | 10285169201486942788 |
21 | 227042177973572054900 |
[1,1,1,4,19,116,835,6890,63826,654552,7354893, 89830770,1184915556,16788863356,254342837905, 4103256660048,70241858430220,1271839899568064, 24287699718766932,487891841580468294, 10285169201486942788,227042177973572054900] |