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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 28 |
| 4 | 130 |
| 5 | 532 |
| 6 | 2528 |
| 7 | 11232 |
| 8 | 54018 |
| 9 | 248164 |
| 10 | 1212082 |
| 11 | 5682304 |
| 12 | 27893742 |
| 13 | 133023140 |
| 14 | 655148986 |
| 15 | 3154342858 |
| 16 | 15603065572 |
| 17 | 75639961162 |
| 18 | 374862248858 |
| 19 | 1828672158604 |
| 20 | 9074950870092 |
| 21 | 44449162462130 |
| 22 | 220966384291864 |
| 23 | 1085680487597732 |
| 24 | 5401935260776376 |
| 25 | 26619308952466454 |
| 26 | 132536670446683276 |
[1,2,8,28,130,532,2528,11232,54018,248164,1212082, 5682304,27893742,133023140,655148986,3154342858, 15603065572,75639961162,374862248858, 1828672158604,9074950870092,44449162462130, 220966384291864,1085680487597732,5401935260776376, 26619308952466454,132536670446683276] |