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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 21 |
| 3 | 121 |
| 4 | 246 |
| 5 | 2121 |
| 6 | 5246 |
| 7 | 52121 |
| 8 | 286496 |
| 9 | 677121 |
| 10 | 677121 |
| 11 | 20208371 |
| 12 | 117864621 |
| 13 | 606145871 |
| 14 | 3047552121 |
| 15 | 3047552121 |
| 16 | 94600286496 |
| 17 | 704951848996 |
| 18 | 2993770208371 |
| 19 | 2993770208371 |
| 20 | 79287715520871 |
| 21 | 270022578802121 |
| 22 | 746859737005246 |
| 23 | 5515231319036496 |
| 24 | 29357089229192746 |
[0,1,21,121,246,2121,5246,52121,286496,677121, 677121,20208371,117864621,606145871,3047552121, 3047552121,94600286496,704951848996,2993770208371, 2993770208371,79287715520871,270022578802121, 746859737005246,5515231319036496, 29357089229192746] |