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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 23 |
| 3 | 78 |
| 4 | 271 |
| 5 | 982 |
| 6 | 3619 |
| 7 | 13454 |
| 8 | 50193 |
| 9 | 187620 |
| 10 | 702063 |
| 11 | 2628392 |
| 12 | 9842791 |
| 13 | 36863984 |
| 14 | 138074989 |
| 15 | 517180630 |
| 16 | 1937210511 |
| 17 | 7256297572 |
| 18 | 27180361021 |
| 19 | 101811374934 |
| 20 | 381362390785 |
| 21 | 1428498083084 |
| 22 | 5350835309773 |
| 23 | 20043038849204 |
| 24 | 75076770609471 |
[4,23,78,271,982,3619,13454,50193,187620,702063, 2628392,9842791,36863984,138074989,517180630, 1937210511,7256297572,27180361021,101811374934, 381362390785,1428498083084,5350835309773, 20043038849204,75076770609471] |