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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 32 |
| 4 | 169 |
| 5 | 976 |
| 6 | 5989 |
| 7 | 38398 |
| 8 | 254509 |
| 9 | 1731596 |
| 10 | 12032874 |
| 11 | 85092944 |
| 12 | 610714311 |
| 13 | 4439136084 |
| 14 | 32626373027 |
| 15 | 242153129074 |
| 16 | 1813069499846 |
| 17 | 13682961621602 |
| 18 | 104014376985334 |
| 19 | 796004610604094 |
| 20 | 6129901459731357 |
| 21 | 47484532009772272 |
[1,2,7,32,169,976,5989,38398,254509,1731596, 12032874,85092944,610714311,4439136084, 32626373027,242153129074,1813069499846, 13682961621602,104014376985334,796004610604094, 6129901459731357,47484532009772272] |