| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 64 |
| 4 | 930 |
| 5 | 17088 |
| 6 | 380870 |
| 7 | 9992064 |
| 8 | 301738626 |
| 9 | 10310669440 |
| 10 | 393355695942 |
| 11 | 16573741095360 |
| 12 | 764401360062626 |
| 13 | 38304552622588224 |
| 14 | 2072335759298438790 |
| 15 | 120390122318741003008 |
| 16 | 7474705606285243345410 |
[1,1,6,64,930,17088,380870,9992064,301738626, 10310669440,393355695942,16573741095360, 764401360062626,38304552622588224, 2072335759298438790,120390122318741003008, 7474705606285243345410] |