The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 26 |
| 5 | 220 |
| 6 | 3622 |
| 7 | 105859 |
| 8 | 5677789 |
| 9 | 553715341 |
| 10 | 98404068313 |
| 11 | 31850967186980 |
| 12 | 18779046566454536 |
| 13 | 20167518569123722322 |
| 14 | 39451359692134386945019 |
[1,2,5,26,220,3622,105859,5677789,553715341, 98404068313,31850967186980,18779046566454536, 20167518569123722322,39451359692134386945019] |