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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 17 |
| 3 | 57 |
| 4 | 456 |
| 5 | 3540 |
| 6 | 24773 |
| 7 | 174927 |
| 8 | 1262270 |
| 9 | 8905776 |
| 10 | 63373156 |
| 11 | 449506816 |
| 12 | 3184860720 |
| 13 | 22596207841 |
| 14 | 160137303788 |
| 15 | 1135302681211 |
| 16 | 8048142435691 |
| 17 | 57049038241053 |
| 18 | 404414221946254 |
| 19 | 2866733296182372 |
| 20 | 20321383697508618 |
[1,17,57,456,3540,24773,174927,1262270,8905776, 63373156,449506816,3184860720,22596207841, 160137303788,1135302681211,8048142435691, 57049038241053,404414221946254,2866733296182372, 20321383697508618] |