The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 64 |
| 4 | 1120 |
| 5 | 42176 |
| 6 | 3583232 |
| 7 | 666124288 |
| 8 | 281268665344 |
| 9 | 260766671206400 |
| 10 | 549874114073747456 |
| 11 | 2547649010961476288512 |
| 12 | 26854416724405008878829568 |
[1,2,8,64,1120,42176,3583232,666124288, 281268665344,260766671206400,549874114073747456, 2547649010961476288512,26854416724405008878829568] |