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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 30 |
| 5 | 75 |
| 6 | 189 |
| 7 | 478 |
| 8 | 1211 |
| 9 | 3076 |
| 10 | 7818 |
| 11 | 19901 |
| 12 | 50680 |
| 13 | 129179 |
| 14 | 329383 |
| 15 | 840336 |
| 16 | 2144540 |
| 17 | 5474889 |
| 18 | 13980493 |
| 19 | 35709394 |
| 20 | 91228015 |
| 21 | 233108456 |
| 22 | 595740568 |
| 23 | 1522725379 |
| 24 | 3892624055 |
| 25 | 9952119054 |
| 26 | 25446913766 |
| 27 | 65072487645 |
[1,2,5,12,30,75,189,478,1211,3076,7818,19901, 50680,129179,329383,840336,2144540,5474889, 13980493,35709394,91228015,233108456,595740568, 1522725379,3892624055,9952119054,25446913766, 65072487645] |