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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 3 |
| 6 | 10 |
| 7 | 33 |
| 8 | 98 |
| 9 | 270 |
| 10 | 738 |
| 11 | 1935 |
| 12 | 5004 |
| 13 | 12580 |
| 14 | 31354 |
| 15 | 76444 |
| 16 | 185305 |
| 17 | 441363 |
| 18 | 1046837 |
| 19 | 2447913 |
| 20 | 5705753 |
| 21 | 13143961 |
| 22 | 30202325 |
| 23 | 68719396 |
| 24 | 156034994 |
| 25 | 351348607 |
| 26 | 789783351 |
| 27 | 1762658134 |
| 28 | 3928209272 |
| 29 | 8700183502 |
| 30 | 19244947618 |
| 31 | 42340195770 |
| 32 | 93049476310 |
| 33 | 203518456343 |
[1,3,10,33,98,270,738,1935,5004,12580,31354,76444, 185305,441363,1046837,2447913,5705753,13143961, 30202325,68719396,156034994,351348607,789783351, 1762658134,3928209272,8700183502,19244947618, 42340195770,93049476310,203518456343] |