The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 17 |
| 6 | 129 |
| 7 | 823 |
| 8 | 16549 |
| 9 | 203762 |
| 10 | 9057969 |
| 11 | 229117047 |
| 12 | 20251050469 |
| 13 | 1099941609906 |
| 14 | 182745344595201 |
| 15 | 21826976698036317 |
| 16 | 6625997170286326085 |
| 17 | 1760792727174811634066 |
| 18 | 963263479575497024110193 |
| 19 | 572732462137043288595101258 |
| 20 | 560867188756075075604736149189 |
[1,1,1,2,5,17,129,823,16549,203762,9057969, 229117047,20251050469,1099941609906, 182745344595201,21826976698036317, 6625997170286326085,1760792727174811634066, 963263479575497024110193, 572732462137043288595101258, 560867188756075075604736149189] |