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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 3 |
| 3 | 21 |
| 4 | 72 |
| 5 | 180 |
| 6 | 375 |
| 7 | 693 |
| 8 | 1176 |
| 9 | 1872 |
| 10 | 2835 |
| 11 | 4125 |
| 12 | 5808 |
| 13 | 7956 |
| 14 | 10647 |
| 15 | 13965 |
| 16 | 18000 |
| 17 | 22848 |
| 18 | 28611 |
| 19 | 35397 |
| 20 | 43320 |
| 21 | 52500 |
| 22 | 63063 |
| 23 | 75141 |
| 24 | 88872 |
| 25 | 104400 |
| 26 | 121875 |
| 27 | 141453 |
| 28 | 163296 |
| 29 | 187572 |
| 30 | 214455 |
| 31 | 244125 |
| 32 | 276768 |
| 33 | 312576 |
| 34 | 351747 |
| 35 | 394485 |
| 36 | 441000 |
[0,0,3,21,72,180,375,693,1176,1872,2835,4125,5808, 7956,10647,13965,18000,22848,28611,35397,43320, 52500,63063,75141,88872,104400,121875,141453, 163296,187572,214455,244125,276768,312576,351747, 394485,441000] |