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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 15 |
| 3 | 105 |
| 4 | 1155 |
| 5 | 85085 |
| 6 | 1616615 |
| 7 | 37182145 |
| 8 | 1078282205 |
| 9 | 247357937827 |
| 10 | 10141675450907 |
| 11 | 436092044389001 |
| 12 | 20496326086283047 |
| 13 | 1086305282573001491 |
| 14 | 64092011671807087969 |
| 15 | 3909612711980232366109 |
| 16 | 261944051702675568529303 |
| 17 | 18598027670889965365580513 |
[1,2,15,105,1155,85085,1616615,37182145, 1078282205,247357937827,10141675450907, 436092044389001,20496326086283047, 1086305282573001491,64092011671807087969, 3909612711980232366109,261944051702675568529303, 18598027670889965365580513] |