The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 14 |
| 2 | 105 |
| 3 | 560 |
| 4 | 2380 |
| 5 | 8568 |
| 6 | 27132 |
| 7 | 77520 |
| 8 | 203490 |
| 9 | 497420 |
| 10 | 1144066 |
| 11 | 2496144 |
| 12 | 5200300 |
| 13 | 10400599 |
| 14 | 20058286 |
| 15 | 37442055 |
| 16 | 67863355 |
| 17 | 119757470 |
| 18 | 206244507 |
| 19 | 347346468 |
| 20 | 573088920 |
| 21 | 927780270 |
| 22 | 1475840380 |
| 23 | 2309645534 |
| 24 | 3559971156 |
| 25 | 5409749996 |
[1,14,105,560,2380,8568,27132,77520,203490,497420, 1144066,2496144,5200300,10400599,20058286, 37442055,67863355,119757470,206244507,347346468, 573088920,927780270,1475840380,2309645534, 3559971156,5409749996] |