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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 16 |
| 4 | 191 |
| 5 | 2136 |
| 6 | 25282 |
| 7 | 318288 |
| 8 | 4141179 |
| 9 | 55011100 |
| 10 | 744023566 |
| 11 | 10218244168 |
| 12 | 142097817686 |
| 13 | 1996654572040 |
| 14 | 28305096013380 |
| 15 | 404343620288016 |
| 16 | 5814760281237459 |
| 17 | 84111739834677030 |
| 18 | 1223022979126528390 |
| 19 | 17865805764222959380 |
| 20 | 262068371593318209826 |
[1,1,1,16,191,2136,25282,318288,4141179,55011100, 744023566,10218244168,142097817686,1996654572040, 28305096013380,404343620288016,5814760281237459, 84111739834677030,1223022979126528390, 17865805764222959380,262068371593318209826] |