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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 257 |
| 4 | 6562 |
| 5 | 72354 |
| 6 | 456418 |
| 7 | 2142595 |
| 8 | 7841860 |
| 9 | 24684612 |
| 10 | 67340708 |
| 11 | 167731333 |
| 12 | 380410598 |
| 13 | 812071910 |
| 14 | 1622037830 |
| 15 | 3103591687 |
| 16 | 5649705096 |
| 17 | 9961449608 |
| 18 | 16894160328 |
| 19 | 27957167625 |
| 20 | 44840730666 |
| 21 | 70540730666 |
| 22 | 108149231146 |
| 23 | 163239463563 |
| 24 | 241120467148 |
| 25 | 351625763020 |
[0,0,257,6562,72354,456418,2142595,7841860, 24684612,67340708,167731333,380410598,812071910, 1622037830,3103591687,5649705096,9961449608, 16894160328,27957167625,44840730666,70540730666, 108149231146,163239463563,241120467148, 351625763020] |