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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 288 |
| 7 | 456 |
| 8 | 488 |
| 9 | 754 |
| 10 | 1699 |
| 11 | 3744 |
| 12 | 7940 |
| 13 | 15748 |
| 14 | 30396 |
| 15 | 60160 |
| 16 | 120944 |
| 17 | 246040 |
| 18 | 499256 |
| 19 | 1004336 |
| 20 | 2016168 |
| 21 | 4044432 |
| 22 | 8130660 |
| 23 | 16373500 |
| 24 | 32966620 |
| 25 | 66358420 |
| 26 | 133489108 |
| 27 | 268489288 |
| 28 | 540125980 |
| 29 | 1086691764 |
| 30 | 2186585680 |
| 31 | 4399583284 |
[1,2,6,24,120,288,456,488,754,1699,3744,7940, 15748,30396,60160,120944,246040,499256,1004336, 2016168,4044432,8130660,16373500,32966620, 66358420,133489108,268489288,540125980,1086691764, 2186585680,4399583284] |