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| n | a(n) |
|---|---|
| 1 | 10 |
| 2 | 100 |
| 3 | 240 |
| 4 | 780 |
| 5 | 2320 |
| 6 | 7140 |
| 7 | 21600 |
| 8 | 65980 |
| 9 | 200400 |
| 10 | 610740 |
| 11 | 1857520 |
| 12 | 5656380 |
| 13 | 17211840 |
| 14 | 52396900 |
| 15 | 159466800 |
| 16 | 485403660 |
| 17 | 1477389520 |
| 18 | 4496881380 |
| 19 | 13687155360 |
| 20 | 41660429500 |
| 21 | 126802853520 |
| 22 | 385955704500 |
| 23 | 1174746099760 |
| 24 | 3575622750780 |
[10,100,240,780,2320,7140,21600,65980,200400, 610740,1857520,5656380,17211840,52396900, 159466800,485403660,1477389520,4496881380, 13687155360,41660429500,126802853520,385955704500, 1174746099760,3575622750780] |