The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 41 |
| 5 | 436 |
| 6 | 5741 |
| 7 | 90481 |
| 8 | 1663585 |
| 9 | 34988311 |
| 10 | 828931049 |
| 11 | 21851881930 |
| 12 | 634556225161 |
| 13 | 20129592507025 |
| 14 | 692665874901013 |
| 15 | 25699370092119569 |
| 16 | 1022757988416562049 |
| 17 | 43461563755791470416 |
| 18 | 1964206882303435582865 |
| 19 | 94076863910519354420761 |
| 20 | 4760163616791818063701801 |
[1,1,1,5,41,436,5741,90481,1663585,34988311, 828931049,21851881930,634556225161,20129592507025, 692665874901013,25699370092119569, 1022757988416562049,43461563755791470416, 1964206882303435582865,94076863910519354420761, 4760163616791818063701801] |