The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 6 | 1 |
| 7 | 30 |
| 8 | 560 |
| 9 | 9440 |
| 10 | 156592 |
| 11 | 2613664 |
| 12 | 44169600 |
| 13 | 756712960 |
| 14 | 13136471040 |
| 15 | 230851792896 |
| 16 | 4102116843520 |
| 17 | 73626174750720 |
| 18 | 1333446495436800 |
| 19 | 24347500823838720 |
| 20 | 447847464256929792 |
| 21 | 8292879605769961472 |
| 22 | 154496591977544417280 |
| 23 | 2894283145228079595520 |
| 24 | 54496565896255729827840 |
| 25 | 1030917988055843180904448 |
[1,30,560,9440,156592,2613664,44169600,756712960, 13136471040,230851792896,4102116843520, 73626174750720,1333446495436800,24347500823838720, 447847464256929792,8292879605769961472, 154496591977544417280,2894283145228079595520, 54496565896255729827840,1030917988055843180904448] |