The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 6 |
| 5 | 1 |
| 6 | 90 |
| 7 | 42 |
| 8 | 2521 |
| 9 | 2268 |
| 10 | 113742 |
| 11 | 166321 |
| 12 | 7543206 |
| 13 | 16218930 |
| 14 | 691242553 |
| 15 | 2044833336 |
| 16 | 83708046246 |
| 17 | 324830941345 |
| 18 | 12951273345282 |
| 19 | 63596620804122 |
| 20 | 2493395633726425 |
| 21 | 15062005915534116 |
| 22 | 584749646165678622 |
| 23 | 4247497704703187089 |
| 24 | 164155618660742879022 |
[1,0,1,0,6,1,90,42,2521,2268,113742,166321, 7543206,16218930,691242553,2044833336,83708046246, 324830941345,12951273345282,63596620804122, 2493395633726425,15062005915534116, 584749646165678622,4247497704703187089, 164155618660742879022] |