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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 14 |
| 5 | 38 |
| 6 | 94 |
| 7 | 248 |
| 8 | 628 |
| 9 | 1638 |
| 10 | 4190 |
| 11 | 10872 |
| 12 | 27940 |
| 13 | 72316 |
| 14 | 186260 |
| 15 | 481488 |
| 16 | 1241512 |
| 17 | 3207302 |
| 18 | 8274646 |
| 19 | 21369496 |
| 20 | 55148068 |
| 21 | 142396436 |
| 22 | 367537484 |
| 23 | 948920560 |
| 24 | 2449445432 |
| 25 | 6323741404 |
| 26 | 16324167564 |
| 27 | 42143003504 |
[1,1,2,6,14,38,94,248,628,1638,4190,10872,27940, 72316,186260,481488,1241512,3207302,8274646, 21369496,55148068,142396436,367537484,948920560, 2449445432,6323741404,16324167564,42143003504] |