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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 21 |
| 3 | 44 |
| 4 | 2397 |
| 5 | 4838 |
| 6 | 50777 |
| 7 | 106392 |
| 8 | 5795945 |
| 9 | 11698282 |
| 10 | 122778765 |
| 11 | 257255812 |
| 12 | 14014592613 |
| 13 | 28286441038 |
| 14 | 296879002993 |
| 15 | 622044447024 |
| 16 | 33887279142289 |
| 17 | 68396602731602 |
| 18 | 717853306458309 |
| 19 | 1504103215648220 |
| 20 | 81939426951462189 |
| 21 | 165382957118572598 |
[1,2,21,44,2397,4838,50777,106392,5795945, 11698282,122778765,257255812,14014592613, 28286441038,296879002993,622044447024, 33887279142289,68396602731602,717853306458309, 1504103215648220,81939426951462189, 165382957118572598] |