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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 888 |
| 6 | 9952 |
| 7 | 58360 |
| 8 | 241600 |
| 9 | 825560 |
| 10 | 2337408 |
| 11 | 5997720 |
| 12 | 13677376 |
| 13 | 29637936 |
| 14 | 58967520 |
| 15 | 112217328 |
| 16 | 203187264 |
| 17 | 356500560 |
| 18 | 595939648 |
| 19 | 978817680 |
| 20 | 1546416960 |
| 21 | 2405951944 |
| 22 | 3652967008 |
| 23 | 5438947528 |
| 24 | 7891156160 |
| 25 | 11396568424 |
| 26 | 16126862080 |
[0,0,0,0,888,9952,58360,241600,825560,2337408, 5997720,13677376,29637936,58967520,112217328, 203187264,356500560,595939648,978817680, 1546416960,2405951944,3652967008,5438947528, 7891156160,11396568424,16126862080] |