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| n | a(n) |
|---|---|
| 1 | 860 |
| 2 | 2948 |
| 3 | 10124 |
| 4 | 34832 |
| 5 | 119932 |
| 6 | 412972 |
| 7 | 1422232 |
| 8 | 4898776 |
| 9 | 16874830 |
| 10 | 58131580 |
| 11 | 200257200 |
| 12 | 689871586 |
| 13 | 2376578686 |
| 14 | 8187255382 |
| 15 | 28204984386 |
| 16 | 97165888404 |
| 17 | 334735779168 |
| 18 | 1153163060226 |
| 19 | 3972642458048 |
| 20 | 13685741942400 |
| 21 | 47147347303294 |
[860,2948,10124,34832,119932,412972,1422232, 4898776,16874830,58131580,200257200,689871586, 2376578686,8187255382,28204984386,97165888404, 334735779168,1153163060226,3972642458048, 13685741942400,47147347303294] |