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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 46 |
| 3 | 104 |
| 4 | 244 |
| 5 | 560 |
| 6 | 1336 |
| 7 | 3104 |
| 8 | 7504 |
| 9 | 17600 |
| 10 | 42976 |
| 11 | 101504 |
| 12 | 249664 |
| 13 | 592640 |
| 14 | 1465216 |
| 15 | 3490304 |
| 16 | 8660224 |
| 17 | 20679680 |
| 18 | 51437056 |
| 19 | 123029504 |
| 20 | 306525184 |
| 21 | 733982720 |
| 22 | 1830762496 |
| 23 | 4387119104 |
| 24 | 10951020544 |
| 25 | 26255605760 |
| 26 | 65571905536 |
| 27 | 157265199104 |
[20,46,104,244,560,1336,3104,7504,17600,42976, 101504,249664,592640,1465216,3490304,8660224, 20679680,51437056,123029504,306525184,733982720, 1830762496,4387119104,10951020544,26255605760, 65571905536,157265199104] |