The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 24 |
| 4 | 416 |
| 5 | 17152 |
| 6 | 996352 |
| 7 | 74691456 |
| 8 | 7245522944 |
| 9 | 896234266624 |
| 10 | 137930480164864 |
| 11 | 25825353123102720 |
| 12 | 5777805863334576128 |
| 13 | 1522101710704028188672 |
| 14 | 466366128918332878225408 |
[0,1,4,24,416,17152,996352,74691456,7245522944, 896234266624,137930480164864,25825353123102720, 5777805863334576128,1522101710704028188672, 466366128918332878225408] |