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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 24 |
| 3 | 312 |
| 4 | 1680 |
| 5 | 16104 |
| 6 | 37128 |
| 7 | 141984 |
| 8 | 247608 |
| 9 | 643632 |
| 10 | 2051112 |
| 11 | 2862912 |
| 12 | 6934392 |
| 13 | 11585616 |
| 14 | 14700840 |
| 15 | 22934496 |
| 16 | 41819544 |
| 17 | 71492424 |
| 18 | 84459624 |
| 19 | 135012504 |
| 20 | 180422928 |
| 21 | 207307152 |
| 22 | 307705632 |
| 23 | 393904056 |
| 24 | 558405936 |
| 25 | 858734016 |
| 26 | 1051010040 |
[3,24,312,1680,16104,37128,141984,247608,643632, 2051112,2862912,6934392,11585616,14700840, 22934496,41819544,71492424,84459624,135012504, 180422928,207307152,307705632,393904056,558405936, 858734016,1051010040] |