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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 130 |
| 5 | 560 |
| 6 | 2515 |
| 7 | 11414 |
| 8 | 52747 |
| 9 | 245438 |
| 10 | 1153428 |
| 11 | 5451143 |
| 12 | 25915808 |
| 13 | 123731198 |
| 14 | 593089167 |
| 15 | 2852055352 |
| 16 | 13755006246 |
| 17 | 66500899299 |
| 18 | 322217412195 |
| 19 | 1564256873782 |
| 20 | 7607081045206 |
| 21 | 37050749287155 |
| 22 | 180708563205005 |
| 23 | 882479863916443 |
| 24 | 4314455261165435 |
| 25 | 21115325837211025 |
| 26 | 103438362436377391 |
[1,2,8,30,130,560,2515,11414,52747,245438,1153428, 5451143,25915808,123731198,593089167,2852055352, 13755006246,66500899299,322217412195, 1564256873782,7607081045206,37050749287155, 180708563205005,882479863916443,4314455261165435, 21115325837211025,103438362436377391] |