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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 26 |
| 5 | 89 |
| 6 | 317 |
| 7 | 1145 |
| 8 | 4349 |
| 9 | 16621 |
| 10 | 65495 |
| 11 | 260108 |
| 12 | 1050890 |
| 13 | 4281295 |
| 14 | 17645035 |
| 15 | 73260909 |
| 16 | 306735774 |
| 17 | 1292685198 |
| 18 | 5481962505 |
| 19 | 23378481403 |
| 20 | 100196337941 |
| 21 | 431455650979 |
| 22 | 1865578740720 |
| 23 | 8098783460584 |
| 24 | 35282359297779 |
| 25 | 154228754828605 |
| 26 | 676247512748650 |
| 27 | 2973761506579073 |
| 28 | 13112269586824177 |
[1,1,3,8,26,89,317,1145,4349,16621,65495,260108, 1050890,4281295,17645035,73260909,306735774, 1292685198,5481962505,23378481403,100196337941, 431455650979,1865578740720,8098783460584, 35282359297779,154228754828605,676247512748650, 2973761506579073,13112269586824177] |