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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 76 |
| 2 | 2578 |
| 3 | 44288 |
| 4 | 478711 |
| 5 | 3710272 |
| 6 | 22393101 |
| 7 | 111200600 |
| 8 | 472211360 |
| 9 | 1763603560 |
| 10 | 5916521021 |
| 11 | 18121655192 |
| 12 | 51328536740 |
| 13 | 135834620472 |
| 14 | 338676787932 |
| 15 | 801091475448 |
| 16 | 1808025242415 |
| 17 | 3912600581712 |
| 18 | 8152010122276 |
| 19 | 16411466716600 |
| 20 | 32022153082291 |
| 21 | 60720959942432 |
| 22 | 112158519503545 |
[1,76,2578,44288,478711,3710272,22393101, 111200600,472211360,1763603560,5916521021, 18121655192,51328536740,135834620472,338676787932, 801091475448,1808025242415,3912600581712, 8152010122276,16411466716600,32022153082291, 60720959942432,112158519503545] |