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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 65 |
| 5 | 184 |
| 6 | 487 |
| 7 | 1254 |
| 8 | 3145 |
| 9 | 7706 |
| 10 | 18480 |
| 11 | 43490 |
| 12 | 100692 |
| 13 | 229472 |
| 14 | 515802 |
| 15 | 1144416 |
| 16 | 2508948 |
| 17 | 5439642 |
| 18 | 11671859 |
| 19 | 24801738 |
| 20 | 52221911 |
| 21 | 109013538 |
| 22 | 225718717 |
| 23 | 463769652 |
| 24 | 945915199 |
| 25 | 1915895576 |
| 26 | 3854803572 |
| 27 | 7706786958 |
| 28 | 15314564282 |
| 29 | 30255672820 |
| 30 | 59440488874 |
[1,2,7,24,65,184,487,1254,3145,7706,18480,43490, 100692,229472,515802,1144416,2508948,5439642, 11671859,24801738,52221911,109013538,225718717, 463769652,945915199,1915895576,3854803572, 7706786958,15314564282,30255672820,59440488874] |