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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 96 |
| 6 | 849 |
| 7 | 9362 |
| 8 | 118061 |
| 9 | 1706576 |
| 10 | 27411888 |
| 11 | 488133552 |
| 12 | 9504647866 |
| 13 | 201394553808 |
| 14 | 4607546125740 |
| 15 | 113271179680136 |
| 16 | 2976610819616004 |
| 17 | 83276079152315904 |
| 18 | 2470817772641667104 |
| 19 | 77492234876034762432 |
| 20 | 2561350116102926727744 |
| 21 | 88984716683633511515904 |
[1,1,3,14,96,849,9362,118061,1706576,27411888, 488133552,9504647866,201394553808,4607546125740, 113271179680136,2976610819616004, 83276079152315904,2470817772641667104, 77492234876034762432,2561350116102926727744, 88984716683633511515904] |