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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 18 |
| 5 | 43 |
| 6 | 112 |
| 7 | 282 |
| 8 | 740 |
| 9 | 1940 |
| 10 | 5182 |
| 11 | 13916 |
| 12 | 37826 |
| 13 | 103391 |
| 14 | 284815 |
| 15 | 788636 |
| 16 | 2195414 |
| 17 | 6137025 |
| 18 | 17223354 |
| 19 | 48495640 |
| 20 | 136961527 |
| 21 | 387819558 |
| 22 | 1100757411 |
| 23 | 3130895452 |
| 24 | 8922294498 |
| 25 | 25470279123 |
| 26 | 72823983735 |
| 27 | 208515456498 |
| 28 | 597824919725 |
| 29 | 1716072103910 |
| 30 | 4931540188084 |
[1,1,3,7,18,43,112,282,740,1940,5182,13916,37826, 103391,284815,788636,2195414,6137025,17223354, 48495640,136961527,387819558,1100757411, 3130895452,8922294498,25470279123,72823983735, 208515456498,597824919725,1716072103910, 4931540188084] |