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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 756 |
| 3 | 20412 |
| 4 | 551124 |
| 5 | 14880348 |
| 6 | 401769396 |
| 7 | 10847773692 |
| 8 | 292889889684 |
| 9 | 7908027021468 |
| 10 | 213516729579636 |
| 11 | 5764951698650172 |
| 12 | 155653695863554644 |
| 13 | 4202649788315975388 |
| 14 | 113471544284531335476 |
| 15 | 3063731695682346057852 |
[1,28,756,20412,551124,14880348,401769396, 10847773692,292889889684,7908027021468, 213516729579636,5764951698650172, 155653695863554644,4202649788315975388, 113471544284531335476,3063731695682346057852] |