The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 69 |
| 5 | 477 |
| 6 | 4167 |
| 7 | 34731 |
| 8 | 333225 |
| 9 | 4058073 |
| 10 | 48535659 |
| 11 | 638782119 |
| 12 | 9690930477 |
| 13 | 146665611765 |
| 14 | 2428164153711 |
| 15 | 44904494549763 |
| 16 | 820664075440593 |
| 17 | 16238018609968689 |
| 18 | 350155700132388435 |
| 19 | 7568774583230565567 |
| 20 | 175171222712837235861 |
| 21 | 4318996957424273510541 |
| 22 | 107317465474650443023383 |
[1,1,3,15,69,477,4167,34731,333225,4058073, 48535659,638782119,9690930477,146665611765, 2428164153711,44904494549763,820664075440593, 16238018609968689,350155700132388435, 7568774583230565567,175171222712837235861, 4318996957424273510541,107317465474650443023383] |