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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 144 |
| 3 | 13932 |
| 4 | 226224 |
| 5 | 1809360 |
| 6 | 9637200 |
| 7 | 39225564 |
| 8 | 131679072 |
| 9 | 382238784 |
| 10 | 990202320 |
| 11 | 2340528300 |
| 12 | 5130339984 |
| 13 | 10556808912 |
| 14 | 20586528144 |
| 15 | 38330476380 |
| 16 | 68553028800 |
| 17 | 118348187904 |
| 18 | 198021287952 |
| 19 | 322219869804 |
| 20 | 511363229040 |
| 21 | 793426309200 |
| 22 | 1206140143824 |
[0,0,144,13932,226224,1809360,9637200,39225564, 131679072,382238784,990202320,2340528300, 5130339984,10556808912,20586528144,38330476380, 68553028800,118348187904,198021287952, 322219869804,511363229040,793426309200, 1206140143824] |