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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 13 |
| 7 | 23 |
| 8 | 73 |
| 9 | 316 |
| 10 | 1171 |
| 11 | 5078 |
| 12 | 33627 |
| 13 | 212172 |
| 14 | 2092051 |
| 15 | 17868818 |
| 16 | 243014937 |
| 17 | 3050949895 |
| 18 | 53472938233 |
[1,1,1,1,1,13,23,73,316,1171,5078,33627,212172, 2092051,17868818,243014937,3050949895,53472938233] |