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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 11 |
| 4 | 87 |
| 5 | 952 |
| 6 | 13513 |
| 7 | 237113 |
| 8 | 5016728 |
| 9 | 125121009 |
| 10 | 3615047527 |
| 11 | 119384499720 |
| 12 | 4455637803543 |
| 13 | 186152008588691 |
| 14 | 8636436319397292 |
| 15 | 441871067839416319 |
| 16 | 24781002306869712365 |
| 17 | 1515279889256750470086 |
| 18 | 100546673139756241189021 |
[1,1,2,11,87,952,13513,237113,5016728,125121009, 3615047527,119384499720,4455637803543, 186152008588691,8636436319397292, 441871067839416319,24781002306869712365, 1515279889256750470086,100546673139756241189021] |