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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 108 |
| 4 | 7614 |
| 5 | 2451762 |
| 6 | 3773520918 |
| 7 | 28927494486144 |
| 8 | 1137959521626242430 |
| 9 | 234471053096681379609150 |
| 10 | 257075108927481255273258364890 |
| 11 | 1518584605077301579030226106654776268 |
| 12 | 48819910122176867311132781943952677374210562 |
[1,1,6,108,7614,2451762,3773520918,28927494486144, 1137959521626242430,234471053096681379609150, 257075108927481255273258364890, 1518584605077301579030226106654776268, 48819910122176867311132781943952677374210562] |