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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 30 |
| 6 | 93 |
| 7 | 294 |
| 8 | 969 |
| 9 | 3282 |
| 10 | 11329 |
| 11 | 39882 |
| 12 | 142295 |
| 13 | 513939 |
| 14 | 1875643 |
| 15 | 6902317 |
| 16 | 25594800 |
| 17 | 95509369 |
| 18 | 358392077 |
| 19 | 1351474090 |
| 20 | 5118071489 |
| 21 | 19456766201 |
| 22 | 74217281735 |
| 23 | 283958971978 |
| 24 | 1089413455030 |
| 25 | 4189811381010 |
| 26 | 16149646794893 |
| 27 | 62374670683636 |
| 28 | 241352432276001 |
| 29 | 935460060376366 |
| 30 | 3631340391953329 |
[1,1,2,4,11,30,93,294,969,3282,11329,39882,142295, 513939,1875643,6902317,25594800,95509369, 358392077,1351474090,5118071489,19456766201, 74217281735,283958971978,1089413455030, 4189811381010,16149646794893,62374670683636, 241352432276001,935460060376366,3631340391953329] |