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| n | a(n) |
|---|---|
| 3 | 16 |
| 4 | 120 |
| 5 | 952 |
| 6 | 7848 |
| 7 | 65580 |
| 8 | 550476 |
| 9 | 4631876 |
| 10 | 39047764 |
| 11 | 329784608 |
| 12 | 2790469092 |
| 13 | 23656401612 |
| 14 | 200928615160 |
| 15 | 1709781846028 |
| 16 | 14575407966156 |
| 17 | 124466311279620 |
| 18 | 1064636218853556 |
| 19 | 9120848372291680 |
| 20 | 78256468639080460 |
| 21 | 672393605270681188 |
| 22 | 5785139333187494936 |
| 23 | 49838058776228021388 |
[16,120,952,7848,65580,550476,4631876,39047764, 329784608,2790469092,23656401612,200928615160, 1709781846028,14575407966156,124466311279620, 1064636218853556,9120848372291680, 78256468639080460,672393605270681188, 5785139333187494936,49838058776228021388] |