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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 1810 |
| 3 | 263844 |
| 4 | 44916498 |
| 5 | 8345319268 |
| 6 | 1640651321764 |
| 7 | 335556407724360 |
| 8 | 70666388112940818 |
| 9 | 15220552520052960516 |
| 10 | 3337324864503769353060 |
| 11 | 742446552655157791828680 |
| 12 | 167167472732516775004539300 |
| 13 | 38021985442071415426063237704 |
| 14 | 8723111727436784830252513497928 |
[1,18,1810,263844,44916498,8345319268, 1640651321764,335556407724360,70666388112940818, 15220552520052960516,3337324864503769353060, 742446552655157791828680, 167167472732516775004539300, 38021985442071415426063237704, 8723111727436784830252513497928] |