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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 46 |
| 4 | 204 |
| 5 | 915 |
| 6 | 4218 |
| 7 | 19712 |
| 8 | 92635 |
| 9 | 439500 |
| 10 | 2097879 |
| 11 | 10045349 |
| 12 | 48320283 |
| 13 | 233190823 |
| 14 | 1127688064 |
| 15 | 5467521609 |
| 16 | 26562531710 |
| 17 | 129235130543 |
| 18 | 629811090988 |
| 19 | 3073516948545 |
| 20 | 15015174203835 |
| 21 | 73438632955616 |
| 22 | 359542851326497 |
| 23 | 1761726779178020 |
| 24 | 8639634327302590 |
| 25 | 42401462680673052 |
| 26 | 208234844528758384 |
[1,3,11,46,204,915,4218,19712,92635,439500, 2097879,10045349,48320283,233190823,1127688064, 5467521609,26562531710,129235130543,629811090988, 3073516948545,15015174203835,73438632955616, 359542851326497,1761726779178020,8639634327302590, 42401462680673052,208234844528758384] |