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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 100 |
| 4 | 816 |
| 5 | 28772 |
| 6 | 497166 |
| 7 | 10872238 |
| 8 | 222626294 |
| 9 | 4556094076 |
| 10 | 94532505000 |
| 11 | 1941906344228 |
| 12 | 40087399972486 |
| 13 | 826150677451514 |
| 14 | 17030503979740618 |
| 15 | 351123996865798068 |
| 16 | 7237977275451164624 |
| 17 | 149217812560349005972 |
[0,2,100,816,28772,497166,10872238,222626294, 4556094076,94532505000,1941906344228, 40087399972486,826150677451514,17030503979740618, 351123996865798068,7237977275451164624, 149217812560349005972] |