The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 6 |
| 3 | 15 |
| 4 | 1596 |
| 5 | 28155 |
| 6 | 2752266 |
| 7 | 152499165 |
| 8 | 18328556616 |
| 9 | 2081907926295 |
| 10 | 342948671262246 |
| 11 | 63036450590713545 |
| 12 | 14410958655520684956 |
| 13 | 3796531150529363706915 |
| 14 | 1173277778862573074248746 |
| 15 | 415134737359852340707539405 |
| 16 | 167697531024902643857808300816 |
| 17 | 76517905142019788108453415876015 |
[1,0,6,15,1596,28155,2752266,152499165, 18328556616,2081907926295,342948671262246, 63036450590713545,14410958655520684956, 3796531150529363706915,1173277778862573074248746, 415134737359852340707539405, 167697531024902643857808300816, 76517905142019788108453415876015] |