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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 35 |
| 6 | 137 |
| 7 | 574 |
| 8 | 2431 |
| 9 | 10534 |
| 10 | 46123 |
| 11 | 204343 |
| 12 | 912967 |
| 13 | 4111375 |
| 14 | 18637303 |
| 15 | 84988775 |
| 16 | 389589095 |
| 17 | 1794280695 |
| 18 | 8298536715 |
| 19 | 38527147681 |
| 20 | 179487103411 |
| 21 | 838820394913 |
| 22 | 3931498654243 |
| 23 | 18475619837816 |
| 24 | 87036536948489 |
| 25 | 410947150379120 |
| 26 | 1944378509186237 |
[1,1,3,9,35,137,574,2431,10534,46123,204343, 912967,4111375,18637303,84988775,389589095, 1794280695,8298536715,38527147681,179487103411, 838820394913,3931498654243,18475619837816, 87036536948489,410947150379120,1944378509186237] |