The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 34 |
| 5 | 172 |
| 6 | 1035 |
| 7 | 7250 |
| 8 | 58002 |
| 9 | 522021 |
| 10 | 5220213 |
| 11 | 57422352 |
| 12 | 689068235 |
| 13 | 8957887058 |
| 14 | 125410418819 |
| 15 | 1881156282285 |
| 16 | 30098500516564 |
| 17 | 511674508781588 |
| 18 | 9210141158068592 |
| 19 | 174992682003303265 |
| 20 | 3499853640066065319 |
[1,2,8,34,172,1035,7250,58002,522021,5220213, 57422352,689068235,8957887058,125410418819, 1881156282285,30098500516564,511674508781588, 9210141158068592,174992682003303265, 3499853640066065319] |