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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 7 |
| 4 | 13 |
| 5 | 23 |
| 6 | 43 |
| 7 | 80 |
| 8 | 156 |
| 9 | 308 |
| 10 | 628 |
| 11 | 1300 |
| 12 | 2754 |
| 13 | 5908 |
| 14 | 12867 |
| 15 | 28306 |
| 16 | 62914 |
| 17 | 140902 |
| 18 | 317887 |
| 19 | 721397 |
| 20 | 1646080 |
| 21 | 3773415 |
| 22 | 8686867 |
| 23 | 20072822 |
| 24 | 46541053 |
| 25 | 108241285 |
| 26 | 252447554 |
| 27 | 590284775 |
| 28 | 1383498325 |
| 29 | 3249679480 |
| 30 | 7648547152 |
[1,2,4,7,13,23,43,80,156,308,628,1300,2754,5908, 12867,28306,62914,140902,317887,721397,1646080, 3773415,8686867,20072822,46541053,108241285, 252447554,590284775,1383498325,3249679480, 7648547152] |