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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 14 |
| 7 | 28 |
| 8 | 56 |
| 9 | 118 |
| 10 | 254 |
| 11 | 541 |
| 12 | 1140 |
| 13 | 2401 |
| 14 | 5074 |
| 15 | 10738 |
| 16 | 22711 |
| 17 | 48001 |
| 18 | 101447 |
| 19 | 214446 |
| 20 | 453355 |
| 21 | 958395 |
| 22 | 2025963 |
| 23 | 4282685 |
| 24 | 9053286 |
| 25 | 19138115 |
| 26 | 40456779 |
| 27 | 85522862 |
| 28 | 180789396 |
| 29 | 382176531 |
| 30 | 807895636 |
| 31 | 1707837203 |
| 32 | 3610252689 |
| 33 | 7631830480 |
[1,1,1,2,6,14,28,56,118,254,541,1140,2401,5074, 10738,22711,48001,101447,214446,453355,958395, 2025963,4282685,9053286,19138115,40456779, 85522862,180789396,382176531,807895636,1707837203, 3610252689,7631830480] |