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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 4 | 6 |
| 5 | 8 |
| 6 | 18 |
| 7 | 40 |
| 8 | 230 |
| 9 | 4296 |
| 10 | 431206 |
| 11 | 162267272 |
| 12 | 201636689772 |
| 13 | 777816803942188 |
| 14 | 9865957936943931980 |
| 15 | 395886667549681689592056 |
| 16 | 53716176608076643470621240097 |
| 17 | 23524515269630339982914646822137232 |
| 18 | 35682168849414944013547274452501783251521 |
[1,2,3,4,6,8,18,40,230,4296,431206,162267272, 201636689772,777816803942188,9865957936943931980, 395886667549681689592056, 53716176608076643470621240097, 23524515269630339982914646822137232, 35682168849414944013547274452501783251521] |