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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 6 |
| 4 | 94 |
| 5 | 285 |
| 6 | 6342 |
| 7 | 44023 |
| 8 | 732740 |
| 9 | 14220153 |
| 10 | 315233605 |
| 11 | 7857947691 |
| 12 | 217541911830 |
| 13 | 6621714803509 |
| 14 | 219780508232663 |
| 15 | 7899055867765455 |
| 16 | 305601002241052936 |
| 17 | 12662255840668015089 |
| 18 | 559390257977596068105 |
| 19 | 26246546675302419239635 |
| 20 | 1303417502979112415328410 |
[1,1,6,94,285,6342,44023,732740,14220153, 315233605,7857947691,217541911830,6621714803509, 219780508232663,7899055867765455, 305601002241052936,12662255840668015089, 559390257977596068105,26246546675302419239635, 1303417502979112415328410] |