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| n | a(n) |
|---|---|
| 2 | 0 |
| 3 | 0 |
| 4 | 324 |
| 5 | 2268 |
| 6 | 8100 |
| 7 | 21060 |
| 8 | 45360 |
| 9 | 86184 |
| 10 | 149688 |
| 11 | 243000 |
| 12 | 374220 |
| 13 | 552420 |
| 14 | 787644 |
| 15 | 1090908 |
| 16 | 1474200 |
| 17 | 1950480 |
| 18 | 2533680 |
| 19 | 3238704 |
| 20 | 4081428 |
| 21 | 5078700 |
| 22 | 6248340 |
| 23 | 7609140 |
| 24 | 9180864 |
| 25 | 10984248 |
| 26 | 13041000 |
| 27 | 15373800 |
| 28 | 18006300 |
| 29 | 20963124 |
[0,0,324,2268,8100,21060,45360,86184,149688, 243000,374220,552420,787644,1090908,1474200, 1950480,2533680,3238704,4081428,5078700,6248340, 7609140,9180864,10984248,13041000,15373800, 18006300,20963124] |