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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 4 |
| 6 | 56 |
| 7 | 543 |
| 8 | 4600 |
| 9 | 36691 |
| 10 | 284370 |
| 11 | 2174352 |
| 12 | 16533360 |
| 13 | 125572259 |
| 14 | 955035260 |
| 15 | 7283925999 |
| 16 | 55755366698 |
| 17 | 428521485446 |
| 18 | 3307587704256 |
| 19 | 25640569219948 |
| 20 | 199621168997272 |
| 21 | 1560661865377319 |
| 22 | 12251246212162453 |
| 23 | 96551383368363609 |
| 24 | 763795078132240253 |
[0,0,0,0,4,56,543,4600,36691,284370,2174352, 16533360,125572259,955035260,7283925999, 55755366698,428521485446,3307587704256, 25640569219948,199621168997272,1560661865377319, 12251246212162453,96551383368363609, 763795078132240253] |