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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 9 |
| 5 | 56 |
| 6 | 300 |
| 7 | 1488 |
| 8 | 7061 |
| 9 | 32617 |
| 10 | 148166 |
| 11 | 666122 |
| 12 | 2976438 |
| 13 | 13256927 |
| 14 | 58977774 |
| 15 | 262470955 |
| 16 | 1169754507 |
| 17 | 5224863646 |
| 18 | 23403066235 |
| 19 | 105163633173 |
| 20 | 474212892828 |
| 21 | 2146200885977 |
| 22 | 9749771934555 |
| 23 | 44458458762351 |
| 24 | 203486694636257 |
| 25 | 934775275401371 |
[1,9,56,300,1488,7061,32617,148166,666122,2976438, 13256927,58977774,262470955,1169754507,5224863646, 23403066235,105163633173,474212892828, 2146200885977,9749771934555,44458458762351, 203486694636257,934775275401371] |