The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 65 |
| 3 | 435 |
| 4 | 3047 |
| 5 | 20805 |
| 6 | 143866 |
| 7 | 994993 |
| 8 | 6892556 |
| 9 | 47747495 |
| 10 | 330696013 |
| 11 | 2290523877 |
| 12 | 15865339426 |
| 13 | 109889859960 |
| 14 | 761143341606 |
| 15 | 5272010289643 |
| 16 | 36516212627935 |
| 17 | 252926973440552 |
| 18 | 1751881144044050 |
| 19 | 12134283040744869 |
| 20 | 84047266827333127 |
[8,65,435,3047,20805,143866,994993,6892556, 47747495,330696013,2290523877,15865339426, 109889859960,761143341606,5272010289643, 36516212627935,252926973440552,1751881144044050, 12134283040744869,84047266827333127] |