The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 4 | 0 |
| 5 | 10 |
| 6 | 60 |
| 7 | 595 |
| 8 | 4512 |
| 9 | 44802 |
| 10 | 457040 |
| 11 | 5159517 |
| 12 | 62939040 |
| 13 | 829049884 |
| 14 | 11727029860 |
| 15 | 177384144795 |
| 16 | 2857827179200 |
| 17 | 48865616001564 |
| 18 | 883930234491000 |
| 19 | 16866107046572417 |
| 20 | 338568863790331200 |
| 21 | 7132984247370166710 |
| 22 | 157374949769998613708 |
[0,10,60,595,4512,44802,457040,5159517,62939040, 829049884,11727029860,177384144795,2857827179200, 48865616001564,883930234491000,16866107046572417, 338568863790331200,7132984247370166710, 157374949769998613708] |