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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 15 |
| 3 | 52 |
| 4 | 141 |
| 5 | 801 |
| 6 | 2950 |
| 7 | 9792 |
| 8 | 47527 |
| 9 | 193530 |
| 10 | 748908 |
| 11 | 3136113 |
| 12 | 12662762 |
| 13 | 51628821 |
| 14 | 215202537 |
| 15 | 877488961 |
| 16 | 3564479615 |
| 17 | 14617739032 |
| 18 | 59930350355 |
| 19 | 245634413693 |
| 20 | 1006434474838 |
| 21 | 4115218924012 |
| 22 | 16838191789089 |
| 23 | 68996553122238 |
| 24 | 282651353770552 |
| 25 | 1157272492569645 |
[1,1,15,52,141,801,2950,9792,47527,193530,748908, 3136113,12662762,51628821,215202537,877488961, 3564479615,14617739032,59930350355,245634413693, 1006434474838,4115218924012,16838191789089, 68996553122238,282651353770552,1157272492569645] |