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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 26 |
| 5 | 92 |
| 6 | 327 |
| 7 | 1193 |
| 8 | 4562 |
| 9 | 17685 |
| 10 | 69588 |
| 11 | 279436 |
| 12 | 1133916 |
| 13 | 4641173 |
| 14 | 19219142 |
| 15 | 80216046 |
| 16 | 336914408 |
| 17 | 1425417925 |
| 18 | 6066920841 |
| 19 | 25945712001 |
| 20 | 111518261524 |
| 21 | 481520271363 |
| 22 | 2087017917106 |
| 23 | 9079448783803 |
| 24 | 39640509733005 |
| 25 | 173602219516008 |
| 26 | 762503437509516 |
| 27 | 3358590618438060 |
| 28 | 14831233518450775 |
[1,1,3,8,26,92,327,1193,4562,17685,69588,279436, 1133916,4641173,19219142,80216046,336914408, 1425417925,6066920841,25945712001,111518261524, 481520271363,2087017917106,9079448783803, 39640509733005,173602219516008,762503437509516, 3358590618438060,14831233518450775] |