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| n | a(n) |
|---|---|
| 1 | 30 |
| 2 | 1206 |
| 3 | 10700 |
| 4 | 57030 |
| 5 | 220050 |
| 6 | 681254 |
| 7 | 1799256 |
| 8 | 4215510 |
| 9 | 8995310 |
| 10 | 17809110 |
| 11 | 33159204 |
| 12 | 58656806 |
| 13 | 99354570 |
| 14 | 162139590 |
| 15 | 256191920 |
| 16 | 393513654 |
| 17 | 589533606 |
| 18 | 863792630 |
| 19 | 1240714620 |
| 20 | 1750468230 |
| 21 | 2429924354 |
| 22 | 3323714406 |
| 23 | 4485394440 |
[30,1206,10700,57030,220050,681254,1799256, 4215510,8995310,17809110,33159204,58656806, 99354570,162139590,256191920,393513654,589533606, 863792630,1240714620,1750468230,2429924354, 3323714406,4485394440] |