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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 18 |
| 5 | 36 |
| 6 | 75 |
| 7 | 145 |
| 8 | 300 |
| 9 | 579 |
| 10 | 1213 |
| 11 | 2322 |
| 12 | 4800 |
| 13 | 9279 |
| 14 | 19421 |
| 15 | 37162 |
| 16 | 77008 |
| 17 | 148007 |
| 18 | 310745 |
| 19 | 594598 |
| 20 | 1232216 |
| 21 | 2368039 |
| 22 | 4971993 |
| 23 | 9513126 |
| 24 | 19715928 |
| 25 | 37888551 |
| 26 | 79551961 |
| 27 | 152209574 |
| 28 | 315455320 |
| 29 | 606216743 |
| 30 | 1272831449 |
| 31 | 2435352742 |
| 32 | 5047285592 |
| 33 | 9699467815 |
[1,2,4,9,18,36,75,145,300,579,1213,2322,4800,9279, 19421,37162,77008,148007,310745,594598,1232216, 2368039,4971993,9513126,19715928,37888551, 79551961,152209574,315455320,606216743,1272831449, 2435352742,5047285592,9699467815] |