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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 20 |
| 5 | 42 |
| 6 | 85 |
| 7 | 173 |
| 8 | 347 |
| 9 | 697 |
| 10 | 1395 |
| 11 | 2792 |
| 12 | 5587 |
| 13 | 11175 |
| 14 | 22352 |
| 15 | 44706 |
| 16 | 89414 |
| 17 | 178830 |
| 18 | 357661 |
| 19 | 715324 |
| 20 | 1430650 |
| 21 | 2861303 |
| 22 | 5722607 |
| 23 | 11445216 |
| 24 | 22890435 |
| 25 | 45780872 |
| 26 | 91561745 |
| 27 | 183123492 |
| 28 | 301029986 |
| 29 | 301029986 |
[1,4,9,20,42,85,173,347,697,1395,2792,5587,11175, 22352,44706,89414,178830,357661,715324,1430650, 2861303,5722607,11445216,22890435,45780872, 91561745,183123492,301029986,301029986] |