| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 19 |
| 5 | 721 |
| 6 | 67264 |
| 7 | 16731459 |
| 8 | 11654912023 |
| 9 | 23649647075402 |
| 10 | 144714747782240313 |
| 11 | 2752761136943759699903 |
| 12 | 167080696204654407079545988 |
| 13 | 33078287865123858428157169233610 |
[0,0,1,19,721,67264,16731459,11654912023, 23649647075402,144714747782240313, 2752761136943759699903, 167080696204654407079545988, 33078287865123858428157169233610] |