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| n | a(n) |
|---|---|
| 1 | 256 |
| 2 | 1976 |
| 3 | 15616 |
| 4 | 124048 |
| 5 | 986388 |
| 6 | 7854572 |
| 7 | 62623348 |
| 8 | 499915248 |
| 9 | 3995675256 |
| 10 | 31974871096 |
| 11 | 256177589404 |
| 12 | 2054827670052 |
| 13 | 16500568550588 |
| 14 | 132647236063288 |
| 15 | 1067478673720944 |
| 16 | 8599383059167200 |
| 17 | 69343765363020324 |
| 18 | 559711476205611868 |
[256,1976,15616,124048,986388,7854572,62623348, 499915248,3995675256,31974871096,256177589404, 2054827670052,16500568550588,132647236063288, 1067478673720944,8599383059167200, 69343765363020324,559711476205611868] |