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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 40 |
| 5 | 203 |
| 6 | 1218 |
| 7 | 8531 |
| 8 | 68249 |
| 9 | 614241 |
| 10 | 6142413 |
| 11 | 67566552 |
| 12 | 810798631 |
| 13 | 10540382214 |
| 14 | 147565350997 |
| 15 | 2213480264955 |
| 16 | 35415684239292 |
| 17 | 602066632067965 |
| 18 | 10837199377223372 |
| 19 | 205906788167244078 |
| 20 | 4118135763344881563 |
[1,3,10,40,203,1218,8531,68249,614241,6142413, 67566552,810798631,10540382214,147565350997, 2213480264955,35415684239292,602066632067965, 10837199377223372,205906788167244078, 4118135763344881563] |