The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | 30 |
| 5 | 100 |
| 6 | 650 |
| 7 | 3150 |
| 8 | 15500 |
| 9 | 78000 |
| 10 | 391250 |
| 11 | 1952500 |
| 12 | 9762500 |
| 13 | 48831250 |
| 14 | 244156250 |
[0,0,6,30,100,650,3150,15500,78000,391250,1952500, 9762500,48831250,244156250] |