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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 322 |
| 3 | 3232 |
| 4 | 21331 |
| 5 | 103222 |
| 6 | 397460 |
| 7 | 1287672 |
| 8 | 3647349 |
| 9 | 9281272 |
| 10 | 21642038 |
| 11 | 46934680 |
| 12 | 95749927 |
| 13 | 185397226 |
| 14 | 343142248 |
| 15 | 610590224 |
| 16 | 1049496105 |
| 17 | 1749325212 |
| 18 | 2836933738 |
| 19 | 4488787184 |
| 20 | 6946186555 |
| 21 | 10534026910 |
| 22 | 15683670652 |
| 23 | 22960578760 |
[20,322,3232,21331,103222,397460,1287672,3647349, 9281272,21642038,46934680,95749927,185397226, 343142248,610590224,1049496105,1749325212, 2836933738,4488787184,6946186555,10534026910, 15683670652,22960578760] |