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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 10 |
| 3 | 24 |
| 4 | 52 |
| 5 | 112 |
| 6 | 240 |
| 7 | 512 |
| 8 | 1060 |
| 9 | 2192 |
| 10 | 4552 |
| 11 | 9440 |
| 12 | 19408 |
| 13 | 39872 |
| 14 | 81984 |
| 15 | 168448 |
| 16 | 342632 |
| 17 | 696736 |
| 18 | 1421200 |
| 19 | 2897856 |
| 20 | 5891872 |
| 21 | 11976064 |
| 22 | 24361856 |
| 23 | 49543168 |
| 24 | 100329952 |
| 25 | 203147136 |
| 26 | 411939264 |
| 27 | 835168512 |
| 28 | 1690383744 |
| 29 | 3420860928 |
[1,4,10,24,52,112,240,512,1060,2192,4552,9440, 19408,39872,81984,168448,342632,696736,1421200, 2897856,5891872,11976064,24361856,49543168, 100329952,203147136,411939264,835168512, 1690383744,3420860928] |