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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 3 |
| 6 | 10 |
| 7 | 10 |
| 8 | 30 |
| 9 | 75 |
| 10 | 220 |
| 11 | 220 |
| 12 | 588 |
| 13 | 588 |
| 14 | 1568 |
| 15 | 3696 |
| 16 | 11616 |
| 17 | 11616 |
| 18 | 30492 |
| 19 | 30492 |
| 20 | 84700 |
| 21 | 173250 |
| 22 | 441000 |
| 23 | 441000 |
| 24 | 1262520 |
| 25 | 2777544 |
| 26 | 6957720 |
| 27 | 16731660 |
| 28 | 43506760 |
| 29 | 43506760 |
| 30 | 98658000 |
| 31 | 98658000 |
| 32 | 277101000 |
| 33 | 541886400 |
| 34 | 1322481600 |
| 35 | 2715495552 |
[1,1,3,3,10,10,30,75,220,220,588,588,1568,3696, 11616,11616,30492,30492,84700,173250,441000, 441000,1262520,2777544,6957720,16731660,43506760, 43506760,98658000,98658000,277101000,541886400, 1322481600,2715495552] |