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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 146 |
| 5 | 159 |
| 6 | 305 |
| 7 | 1074 |
| 8 | 2453 |
| 9 | 5980 |
| 10 | 20393 |
| 11 | 26373 |
| 12 | 46766 |
| 13 | 540799 |
| 14 | 2209962 |
| 15 | 4960723 |
| 16 | 7170685 |
| 17 | 248764013 |
| 18 | 255934698 |
| 19 | 760633409 |
| 20 | 3298468334 |
| 21 | 37043785083 |
| 22 | 40342253417 |
| 23 | 77386038500 |
| 24 | 272500368917 |
| 25 | 622386776334 |
| 26 | 1517273921585 |
| 27 | 5174208541089 |
| 28 | 6691482462674 |
[1,1,3,13,146,159,305,1074,2453,5980,20393,26373, 46766,540799,2209962,4960723,7170685,248764013, 255934698,760633409,3298468334,37043785083, 40342253417,77386038500,272500368917,622386776334, 1517273921585,5174208541089,6691482462674] |