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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 20 |
| 6 | 50 |
| 7 | 104 |
| 8 | 258 |
| 9 | 552 |
| 10 | 1362 |
| 11 | 2972 |
| 12 | 7306 |
| 13 | 16172 |
| 14 | 39650 |
| 15 | 88720 |
| 16 | 217090 |
| 17 | 489872 |
| 18 | 1196834 |
| 19 | 2719028 |
| 20 | 6634890 |
| 21 | 15157188 |
| 22 | 36949266 |
| 23 | 84799992 |
| 24 | 206549250 |
| 25 | 475894200 |
| 26 | 1158337650 |
| 27 | 2677788492 |
| 28 | 6513914634 |
| 29 | 15102309468 |
| 30 | 36718533570 |
| 31 | 85347160608 |
[1,1,2,4,10,20,50,104,258,552,1362,2972,7306, 16172,39650,88720,217090,489872,1196834,2719028, 6634890,15157188,36949266,84799992,206549250, 475894200,1158337650,2677788492,6513914634, 15102309468,36718533570,85347160608] |