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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 12 |
| 6 | 46 |
| 7 | 251 |
| 8 | 1576 |
| 9 | 11578 |
| 10 | 94933 |
| 11 | 875134 |
| 12 | 8900088 |
| 13 | 99276703 |
| 14 | 1214131109 |
| 15 | 16107824706 |
| 16 | 229757728186 |
| 17 | 3499486564517 |
| 18 | 56862172844198 |
| 19 | 980725126968577 |
| 20 | 17899265342632635 |
| 21 | 345197504845310134 |
| 22 | 7005723403640260805 |
| 23 | 149261757412790940113 |
| 24 | 3329108788695272565243 |
[1,1,1,2,4,12,46,251,1576,11578,94933,875134, 8900088,99276703,1214131109,16107824706, 229757728186,3499486564517,56862172844198, 980725126968577,17899265342632635, 345197504845310134,7005723403640260805, 149261757412790940113,3329108788695272565243] |