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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 26 |
| 5 | 86 |
| 6 | 309 |
| 7 | 1112 |
| 8 | 4300 |
| 9 | 16355 |
| 10 | 64610 |
| 11 | 258460 |
| 12 | 1049577 |
| 13 | 4289188 |
| 14 | 17767640 |
| 15 | 74236553 |
| 16 | 312798334 |
| 17 | 1323001687 |
| 18 | 5645624363 |
| 19 | 24239460347 |
| 20 | 104391408045 |
| 21 | 451959306066 |
| 22 | 1967440956925 |
| 23 | 8589297566724 |
| 24 | 37631972874233 |
| 25 | 165505946315394 |
| 26 | 730191658379518 |
| 27 | 3230280805363359 |
| 28 | 14327178302247607 |
[1,1,3,8,26,86,309,1112,4300,16355,64610,258460, 1049577,4289188,17767640,74236553,312798334, 1323001687,5645624363,24239460347,104391408045, 451959306066,1967440956925,8589297566724, 37631972874233,165505946315394,730191658379518, 3230280805363359,14327178302247607] |