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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 116 |
| 4 | 2082 |
| 5 | 49774 |
| 6 | 1525752 |
| 7 | 58180632 |
| 8 | 2694333744 |
| 9 | 148623965136 |
| 10 | 9611353576800 |
| 11 | 719080605842400 |
| 12 | 61545135592056960 |
| 13 | 5968396255982428800 |
| 14 | 650359540100397012480 |
| 15 | 79053322881277342886400 |
| 16 | 10650510963204404347238400 |
| 17 | 1581353364394671905218406400 |
[0,1,9,116,2082,49774,1525752,58180632,2694333744, 148623965136,9611353576800,719080605842400, 61545135592056960,5968396255982428800, 650359540100397012480,79053322881277342886400, 10650510963204404347238400, 1581353364394671905218406400] |