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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 48 |
| 4 | 240 |
| 5 | 407 |
| 6 | 5920 |
| 7 | 5921 |
| 8 | 2918379 |
| 9 | 7444416 |
| 10 | 18125436 |
| 11 | 210897052 |
| 12 | 6303187514 |
| 13 | 8948360198 |
| 14 | 10462450356 |
| 15 | 11647261846 |
| 16 | 18107015789 |
| 17 | 27434621679 |
| 18 | 31332052290 |
| 19 | 4986706842391 |
| 20 | 485927682264092 |
| 21 | 1287253463537089 |
| 22 | 126835771455251081 |
| 23 | 559018292730428520 |
| 24 | 559018292730428521 |
[0,1,48,240,407,5920,5921,2918379,7444416, 18125436,210897052,6303187514,8948360198, 10462450356,11647261846,18107015789,27434621679, 31332052290,4986706842391,485927682264092, 1287253463537089,126835771455251081, 559018292730428520,559018292730428521] |