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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 248 |
| 3 | 3875 |
| 4 | 31124 |
| 5 | 181753 |
| 6 | 871627 |
| 7 | 3623869 |
| 8 | 13496501 |
| 9 | 46070247 |
| 10 | 146447007 |
| 11 | 438436131 |
| 12 | 1246840863 |
| 13 | 3390992753 |
| 14 | 8867414995 |
| 15 | 22393107641 |
| 16 | 54807572758 |
| 17 | 130403285724 |
| 18 | 302393467628 |
| 19 | 684927912490 |
| 20 | 1518200420906 |
| 21 | 3298704166389 |
| 22 | 7035880460575 |
| 23 | 14750661826629 |
[1,0,248,3875,31124,181753,871627,3623869, 13496501,46070247,146447007,438436131,1246840863, 3390992753,8867414995,22393107641,54807572758, 130403285724,302393467628,684927912490, 1518200420906,3298704166389,7035880460575, 14750661826629] |