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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 31 |
| 4 | 222 |
| 5 | 1807 |
| 6 | 16485 |
| 7 | 166657 |
| 8 | 1849712 |
| 9 | 22363201 |
| 10 | 292571325 |
| 11 | 4118361751 |
| 12 | 62067997590 |
| 13 | 997206323191 |
| 14 | 17014575491837 |
| 15 | 307259565176257 |
| 16 | 5854946313840720 |
| 17 | 117406185841990657 |
| 18 | 2471384848995644517 |
| 19 | 54487872863746170031 |
| 20 | 1255692460715157555230 |
[0,1,5,31,222,1807,16485,166657,1849712,22363201, 292571325,4118361751,62067997590,997206323191, 17014575491837,307259565176257,5854946313840720, 117406185841990657,2471384848995644517, 54487872863746170031,1255692460715157555230] |