The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 168 |
| 3 | 2424 |
| 4 | 35400 |
| 5 | 520236 |
| 6 | 7674144 |
| 7 | 113482584 |
| 8 | 1681028136 |
| 9 | 24932533800 |
| 10 | 370144424376 |
| 11 | 5499182587416 |
| 12 | 81748907485248 |
| 13 | 1215834858032820 |
| 14 | 18090048027643200 |
| 15 | 269246037610828656 |
| 16 | 4008495234662771688 |
[1,12,168,2424,35400,520236,7674144,113482584, 1681028136,24932533800,370144424376,5499182587416, 81748907485248,1215834858032820,18090048027643200, 269246037610828656,4008495234662771688] |