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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 28 |
| 3 | 146 |
| 4 | 627 |
| 5 | 2471 |
| 6 | 9292 |
| 7 | 33878 |
| 8 | 120771 |
| 9 | 423251 |
| 10 | 1463908 |
| 11 | 5011690 |
| 12 | 17021179 |
| 13 | 57450167 |
| 14 | 192966908 |
| 15 | 645696454 |
| 16 | 2154226075 |
| 17 | 7170606795 |
| 18 | 23825657596 |
| 19 | 79055534746 |
| 20 | 262031761435 |
| 21 | 867792229799 |
| 22 | 2872103661988 |
| 23 | 9501035284286 |
| 24 | 31417942222787 |
| 25 | 103862506390523 |
| 26 | 343276150243020 |
[3,28,146,627,2471,9292,33878,120771,423251, 1463908,5011690,17021179,57450167,192966908, 645696454,2154226075,7170606795,23825657596, 79055534746,262031761435,867792229799, 2872103661988,9501035284286,31417942222787, 103862506390523,343276150243020] |