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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 266 |
| 3 | 703 |
| 4 | 4997 |
| 5 | 13091 |
| 6 | 49989 |
| 7 | 122474 |
| 8 | 360753 |
| 9 | 828400 |
| 10 | 2087644 |
| 11 | 4524014 |
| 12 | 10306531 |
| 13 | 21258834 |
| 14 | 45004122 |
| 15 | 88974283 |
| 16 | 178190303 |
| 17 | 339675540 |
| 18 | 650850434 |
| 19 | 1202008572 |
| 20 | 2221390339 |
| 21 | 3990403142 |
| 22 | 7153670354 |
| 23 | 12539899946 |
| 24 | 21903187213 |
| 25 | 37568267009 |
| 26 | 64150343834 |
[1,0,266,703,4997,13091,49989,122474,360753, 828400,2087644,4524014,10306531,21258834,45004122, 88974283,178190303,339675540,650850434,1202008572, 2221390339,3990403142,7153670354,12539899946, 21903187213,37568267009,64150343834] |