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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 5 |
| 3 | 14 |
| 4 | 54 |
| 5 | 158 |
| 6 | 475 |
| 7 | 1340 |
| 8 | 3740 |
| 9 | 10204 |
| 10 | 27521 |
| 11 | 73354 |
| 12 | 193842 |
| 13 | 508346 |
| 14 | 1324791 |
| 15 | 3433720 |
| 16 | 8858104 |
| 17 | 22757432 |
| 18 | 58253885 |
| 19 | 148634502 |
| 20 | 378142446 |
| 21 | 959527766 |
| 22 | 2429034323 |
| 23 | 6135877428 |
| 24 | 15469187604 |
| 25 | 38929330452 |
| 26 | 97806402617 |
| 27 | 245354321666 |
[0,5,14,54,158,475,1340,3740,10204,27521,73354, 193842,508346,1324791,3433720,8858104,22757432, 58253885,148634502,378142446,959527766,2429034323, 6135877428,15469187604,38929330452,97806402617, 245354321666] |