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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 41 |
| 5 | 364 |
| 6 | 4409 |
| 7 | 67573 |
| 8 | 1248626 |
| 9 | 26948347 |
| 10 | 664414997 |
| 11 | 18409263772 |
| 12 | 566018365445 |
| 13 | 19117946453041 |
| 14 | 703533848468330 |
| 15 | 28013710891743007 |
| 16 | 1199943043040160401 |
| 17 | 55013996422974758476 |
| 18 | 2687888298887895948065 |
| 19 | 139414898768304344206141 |
[1,1,2,7,41,364,4409,67573,1248626,26948347, 664414997,18409263772,566018365445,19117946453041, 703533848468330,28013710891743007, 1199943043040160401,55013996422974758476, 2687888298887895948065,139414898768304344206141] |