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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 39 |
| 6 | 127 |
| 7 | 405 |
| 8 | 1330 |
| 9 | 4478 |
| 10 | 15616 |
| 11 | 54421 |
| 12 | 194793 |
| 13 | 701786 |
| 14 | 2564926 |
| 15 | 9449251 |
| 16 | 35159072 |
| 17 | 131736416 |
| 18 | 497409539 |
| 19 | 1889423167 |
| 20 | 7221080327 |
| 21 | 27736071934 |
| 22 | 107096007187 |
| 23 | 415304492985 |
| 24 | 1617344292663 |
| 25 | 6323198767440 |
| 26 | 24810334125175 |
| 27 | 97678055944085 |
| 28 | 385775749723266 |
| 29 | 1528103771029808 |
| 30 | 6070079843420190 |
[1,1,2,5,15,39,127,405,1330,4478,15616,54421, 194793,701786,2564926,9449251,35159072,131736416, 497409539,1889423167,7221080327,27736071934, 107096007187,415304492985,1617344292663, 6323198767440,24810334125175,97678055944085, 385775749723266,1528103771029808,6070079843420190] |