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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 46 |
| 6 | 192 |
| 7 | 840 |
| 8 | 3584 |
| 9 | 15392 |
| 10 | 65536 |
| 11 | 278656 |
| 12 | 1179648 |
| 13 | 4981248 |
| 14 | 20971520 |
| 15 | 88082432 |
| 16 | 369098752 |
| 17 | 1543512064 |
| 18 | 6442450944 |
| 19 | 26843578368 |
| 20 | 111669149696 |
| 21 | 463856599040 |
| 22 | 1924145348608 |
| 23 | 7971459825664 |
| 24 | 32985348833280 |
| 25 | 136339443941376 |
| 26 | 562949953421312 |
[1,1,3,10,46,192,840,3584,15392,65536,278656, 1179648,4981248,20971520,88082432,369098752, 1543512064,6442450944,26843578368,111669149696, 463856599040,1924145348608,7971459825664, 32985348833280,136339443941376,562949953421312] |