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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 8 |
| 5 | 20 |
| 6 | 94 |
| 7 | 438 |
| 8 | 2766 |
| 9 | 19480 |
| 10 | 163058 |
| 11 | 1546726 |
| 12 | 16598282 |
| 13 | 197708058 |
| 14 | 2586423174 |
| 15 | 36769177348 |
| 16 | 563504645310 |
| 17 | 9248221393974 |
| 18 | 161670971937362 |
| 19 | 2996936692836754 |
| 20 | 58689061747521430 |
| 21 | 1210222434323163704 |
| 22 | 26204614054454840842 |
| 23 | 594313769819021397534 |
| 24 | 14086979362268860896282 |
[1,2,2,8,20,94,438,2766,19480,163058,1546726, 16598282,197708058,2586423174,36769177348, 563504645310,9248221393974,161670971937362, 2996936692836754,58689061747521430, 1210222434323163704,26204614054454840842, 594313769819021397534,14086979362268860896282] |