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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 18 |
| 5 | 59 |
| 6 | 235 |
| 7 | 893 |
| 8 | 3810 |
| 9 | 15513 |
| 10 | 68355 |
| 11 | 291633 |
| 12 | 1316392 |
| 13 | 5780793 |
| 14 | 26499220 |
| 15 | 118934221 |
| 16 | 551889602 |
| 17 | 2515299167 |
| 18 | 11775715141 |
| 19 | 54333877955 |
| 20 | 256237560742 |
| 21 | 1193389613255 |
| 22 | 5660224648326 |
| 23 | 26567605325073 |
| 24 | 126621506371332 |
| 25 | 598025706185715 |
| 26 | 2861510181706267 |
| 27 | 13586615488837211 |
| 28 | 65234679563225012 |
[1,1,2,5,18,59,235,893,3810,15513,68355,291633, 1316392,5780793,26499220,118934221,551889602, 2515299167,11775715141,54333877955,256237560742, 1193389613255,5660224648326,26567605325073, 126621506371332,598025706185715,2861510181706267, 13586615488837211,65234679563225012] |