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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 10 |
| 3 | 46 |
| 4 | 244 |
| 5 | 1252 |
| 6 | 6472 |
| 7 | 33400 |
| 8 | 172432 |
| 9 | 890128 |
| 10 | 4595104 |
| 11 | 23721184 |
| 12 | 122455360 |
| 13 | 632148544 |
| 14 | 3263326336 |
| 15 | 16846196608 |
| 16 | 86964744448 |
| 17 | 448936157440 |
| 18 | 2317533096448 |
| 19 | 11963749330432 |
| 20 | 61760195900416 |
| 21 | 318823279584256 |
[1,10,46,244,1252,6472,33400,172432,890128, 4595104,23721184,122455360,632148544,3263326336, 16846196608,86964744448,448936157440, 2317533096448,11963749330432,61760195900416, 318823279584256] |