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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 131 |
| 5 | 796 |
| 6 | 5008 |
| 7 | 36202 |
| 8 | 281003 |
| 9 | 2399224 |
| 10 | 22679301 |
| 11 | 222569004 |
| 12 | 2236648234 |
| 13 | 23354177528 |
| 14 | 248211165052 |
| 15 | 2905273285888 |
| 16 | 35462586540039 |
| 17 | 444348395841976 |
| 18 | 5844562089950893 |
| 19 | 78628980833594936 |
| 20 | 1092348171981581852 |
| 21 | 15331829536310136066 |
[2,7,24,131,796,5008,36202,281003,2399224, 22679301,222569004,2236648234,23354177528, 248211165052,2905273285888,35462586540039, 444348395841976,5844562089950893, 78628980833594936,1092348171981581852, 15331829536310136066] |