The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 80 |
| 4 | 874 |
| 5 | 12092 |
| 6 | 202384 |
| 7 | 3973580 |
| 8 | 89515690 |
| 9 | 2275453700 |
| 10 | 64418414380 |
| 11 | 2009835207800 |
| 12 | 68512342137040 |
| 13 | 2533368817192280 |
| 14 | 100991942945221660 |
| 15 | 4317627768285138020 |
| 16 | 197054129197204173610 |
| 17 | 9562339765515442736180 |
[1,2,10,80,874,12092,202384,3973580,89515690, 2275453700,64418414380,2009835207800, 68512342137040,2533368817192280, 100991942945221660,4317627768285138020, 197054129197204173610,9562339765515442736180] |