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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 44 |
| 4 | 548 |
| 5 | 8808 |
| 6 | 173352 |
| 7 | 4036288 |
| 8 | 108507968 |
| 9 | 3307368320 |
| 10 | 112703108480 |
| 11 | 4245680193024 |
| 12 | 175200825481728 |
| 13 | 7859411394860032 |
| 14 | 380810598813553664 |
| 15 | 19819617775693512704 |
| 16 | 1102737068471914938368 |
| 17 | 65316500202537025634304 |
| 18 | 4103422475123595857854464 |
[1,1,5,44,548,8808,173352,4036288,108507968, 3307368320,112703108480,4245680193024, 175200825481728,7859411394860032, 380810598813553664,19819617775693512704, 1102737068471914938368,65316500202537025634304, 4103422475123595857854464] |