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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 20 |
| 3 | 80 |
| 4 | 320 |
| 5 | 1280 |
| 6 | 5120 |
| 7 | 20480 |
| 8 | 81920 |
| 9 | 327670 |
| 10 | 1310640 |
| 11 | 5242410 |
| 12 | 20969040 |
| 13 | 83873760 |
| 14 | 335485440 |
| 15 | 1341903360 |
| 16 | 5367459840 |
| 17 | 21469224960 |
| 18 | 85874442330 |
| 19 | 343487939580 |
| 20 | 1373912440470 |
| 21 | 5495492494980 |
| 22 | 21981340930320 |
| 23 | 87922847594880 |
[1,5,20,80,320,1280,5120,20480,81920,327670, 1310640,5242410,20969040,83873760,335485440, 1341903360,5367459840,21469224960,85874442330, 343487939580,1373912440470,5495492494980, 21981340930320,87922847594880] |