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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 75 |
| 5 | 757 |
| 6 | 9955 |
| 7 | 161608 |
| 8 | 3149491 |
| 9 | 72294325 |
| 10 | 1919933126 |
| 11 | 58189667167 |
| 12 | 1991123304634 |
| 13 | 76201510956909 |
| 14 | 3235630545496281 |
| 15 | 151399102211450842 |
| 16 | 7760065212106661217 |
| 17 | 433404831023513573519 |
| 18 | 26253103133315432898270 |
| 19 | 1717576707472491422233436 |
| 20 | 120912301935843736344714288 |
[1,1,2,10,75,757,9955,161608,3149491,72294325, 1919933126,58189667167,1991123304634, 76201510956909,3235630545496281, 151399102211450842,7760065212106661217, 433404831023513573519,26253103133315432898270, 1717576707472491422233436, 120912301935843736344714288] |