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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 20 |
| 5 | 57 |
| 6 | 196 |
| 7 | 652 |
| 8 | 2305 |
| 9 | 8187 |
| 10 | 29938 |
| 11 | 110468 |
| 12 | 415523 |
| 13 | 1576423 |
| 14 | 6054903 |
| 15 | 23444901 |
| 16 | 91538346 |
| 17 | 359866575 |
| 18 | 1424136635 |
| 19 | 5667087376 |
| 20 | 22676094964 |
| 21 | 91152587752 |
| 22 | 368075554103 |
| 23 | 1492157429875 |
| 24 | 6072007615541 |
| 25 | 24792251075928 |
| 26 | 101557819189515 |
| 27 | 417226553637568 |
| 28 | 1718945886662743 |
[1,1,3,6,20,57,196,652,2305,8187,29938,110468, 415523,1576423,6054903,23444901,91538346, 359866575,1424136635,5667087376,22676094964, 91152587752,368075554103,1492157429875, 6072007615541,24792251075928,101557819189515, 417226553637568,1718945886662743] |