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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 6 |
| 4 | 6 |
| 5 | 0 |
| 6 | 4 |
| 7 | 28 |
| 8 | 106 |
| 9 | 282 |
| 10 | 660 |
| 11 | 1496 |
| 12 | 3344 |
| 13 | 7176 |
| 14 | 14616 |
| 15 | 27560 |
| 16 | 47672 |
| 17 | 76092 |
| 18 | 112416 |
| 19 | 148808 |
| 20 | 166960 |
| 21 | 148848 |
| 22 | 98560 |
| 23 | 43424 |
| 24 | 10792 |
[1,4,6,6,0,4,28,106,282,660,1496,3344,7176,14616, 27560,47672,76092,112416,148808,166960,148848, 98560,43424,10792] |