The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 9 |
| 7 | 16 |
| 8 | 35 |
| 9 | 70 |
| 10 | 150 |
| 11 | 336 |
| 12 | 770 |
| 13 | 1848 |
| 14 | 4455 |
| 15 | 10920 |
| 16 | 27648 |
| 17 | 70720 |
| 18 | 185895 |
| 19 | 496125 |
| 20 | 1344000 |
| 21 | 3706560 |
| 22 | 10395840 |
| 23 | 29568000 |
| 24 | 85299200 |
| 25 | 249356800 |
| 26 | 738840960 |
| 27 | 2216522880 |
| 28 | 6730407936 |
| 29 | 20678434920 |
| 30 | 64248260076 |
| 31 | 201838500864 |
[2,3,5,9,16,35,70,150,336,770,1848,4455,10920, 27648,70720,185895,496125,1344000,3706560, 10395840,29568000,85299200,249356800,738840960, 2216522880,6730407936,20678434920,64248260076, 201838500864] |