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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 45 |
| 6 | 149 |
| 7 | 509 |
| 8 | 1756 |
| 9 | 6082 |
| 10 | 21246 |
| 11 | 74125 |
| 12 | 260940 |
| 13 | 917060 |
| 14 | 3251573 |
| 15 | 11514563 |
| 16 | 41115372 |
| 17 | 146687475 |
| 18 | 527318119 |
| 19 | 1894548198 |
| 20 | 6853413645 |
| 21 | 24782205276 |
| 22 | 90165044683 |
| 23 | 327958242274 |
| 24 | 1199475359682 |
| 25 | 4386106532923 |
| 26 | 16118279172044 |
| 27 | 59223681674225 |
[1,1,2,5,14,45,149,509,1756,6082,21246,74125, 260940,917060,3251573,11514563,41115372,146687475, 527318119,1894548198,6853413645,24782205276, 90165044683,327958242274,1199475359682, 4386106532923,16118279172044,59223681674225] |