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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 4 |
| 2 | 7 |
| 3 | 13 |
| 4 | 23 |
| 5 | 42 |
| 6 | 75 |
| 7 | 136 |
| 8 | 244 |
| 9 | 441 |
| 10 | 793 |
| 11 | 1431 |
| 12 | 2576 |
| 13 | 4645 |
| 14 | 8366 |
| 15 | 15080 |
| 16 | 27167 |
| 17 | 48961 |
| 18 | 88215 |
| 19 | 158970 |
| 20 | 286439 |
| 21 | 516164 |
| 22 | 930072 |
| 23 | 1675961 |
| 24 | 3019941 |
| 25 | 5441791 |
| 26 | 9805712 |
| 27 | 17669353 |
| 28 | 31838986 |
| 29 | 57371980 |
| 30 | 103380599 |
| 31 | 186285573 |
| 32 | 335674791 |
| 33 | 604865338 |
| 34 | 1089929347 |
[2,4,7,13,23,42,75,136,244,441,793,1431,2576,4645, 8366,15080,27167,48961,88215,158970,286439,516164, 930072,1675961,3019941,5441791,9805712,17669353, 31838986,57371980,103380599,186285573,335674791, 604865338,1089929347] |