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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 44 |
| 5 | 184 |
| 6 | 790 |
| 7 | 3450 |
| 8 | 15242 |
| 9 | 67895 |
| 10 | 304267 |
| 11 | 1369761 |
| 12 | 6188002 |
| 13 | 28031111 |
| 14 | 127253141 |
| 15 | 578694237 |
| 16 | 2635356807 |
| 17 | 12015117401 |
| 18 | 54831125131 |
| 19 | 250418753498 |
| 20 | 1144434017309 |
[1,3,11,44,184,790,3450,15242,67895,304267, 1369761,6188002,28031111,127253141,578694237, 2635356807,12015117401,54831125131,250418753498, 1144434017309] |