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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 12 |
| 6 | 23 |
| 7 | 90 |
| 8 | 162 |
| 9 | 611 |
| 10 | 2402 |
| 11 | 8560 |
| 12 | 32187 |
| 13 | 246141 |
| 14 | 874521 |
| 15 | 6300203 |
| 16 | 48576212 |
| 17 | 330649842 |
| 18 | 2414376086 |
| 19 | 35637800561 |
| 20 | 246608696517 |
| 21 | 3459350545304 |
| 22 | 51985154551969 |
| 23 | 691390369850685 |
| 24 | 9855466810408009 |
| 25 | 284813053880252248 |
[1,2,2,4,8,12,23,90,162,611,2402,8560,32187, 246141,874521,6300203,48576212,330649842, 2414376086,35637800561,246608696517,3459350545304, 51985154551969,691390369850685,9855466810408009, 284813053880252248] |