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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 35 |
| 4 | 195 |
| 5 | 1265 |
| 6 | 7405 |
| 7 | 46435 |
| 8 | 277995 |
| 9 | 1716865 |
| 10 | 10383605 |
| 11 | 63688835 |
| 12 | 386967795 |
| 13 | 2366156465 |
| 14 | 14406507805 |
| 15 | 87966927235 |
| 16 | 536096549595 |
| 17 | 3271366280065 |
| 18 | 19945146300005 |
| 19 | 121674449601635 |
| 20 | 741977556703395 |
| 21 | 4525816353447665 |
[1,5,35,195,1265,7405,46435,277995,1716865, 10383605,63688835,386967795,2366156465, 14406507805,87966927235,536096549595, 3271366280065,19945146300005,121674449601635, 741977556703395,4525816353447665] |