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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 4 |
| 3 | 55 |
| 4 | 128 |
| 5 | 228 |
| 6 | 1721 |
| 7 | 5663 |
| 8 | 11909 |
| 9 | 69946 |
| 10 | 220363 |
| 11 | 570699 |
| 12 | 2878602 |
| 13 | 8802473 |
| 14 | 26886516 |
| 15 | 121529632 |
| 16 | 369658890 |
| 17 | 1215513262 |
| 18 | 5099671734 |
| 19 | 15392472866 |
| 20 | 53972192998 |
| 21 | 212784319669 |
| 22 | 651213834921 |
| 23 | 2381746719520 |
| 24 | 8889638737979 |
[7,4,55,128,228,1721,5663,11909,69946,220363, 570699,2878602,8802473,26886516,121529632, 369658890,1215513262,5099671734,15392472866, 53972192998,212784319669,651213834921, 2381746719520,8889638737979] |