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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 24 |
| 3 | 63 |
| 4 | 264 |
| 5 | 1374 |
| 6 | 3114 |
| 7 | 8937 |
| 8 | 60663 |
| 9 | 94863 |
| 10 | 545793 |
| 11 | 1989417 |
| 12 | 5477133 |
| 13 | 20736417 |
| 14 | 82395387 |
| 15 | 260191833 |
| 16 | 706399164 |
| 17 | 2428989417 |
| 18 | 9380293167 |
| 19 | 28105157886 |
| 20 | 99497231067 |
| 21 | 538479339417 |
| 22 | 1974763271886 |
| 23 | 4472135831667 |
| 24 | 14106593458167 |
| 25 | 62441868958167 |
| 26 | 244744764757083 |
| 27 | 836594274358167 |
[0,3,24,63,264,1374,3114,8937,60663,94863,545793, 1989417,5477133,20736417,82395387,260191833, 706399164,2428989417,9380293167,28105157886, 99497231067,538479339417,1974763271886, 4472135831667,14106593458167,62441868958167, 244744764757083,836594274358167] |