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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 10 |
| 3 | 40 |
| 4 | 148 |
| 5 | 526 |
| 6 | 1828 |
| 7 | 6256 |
| 8 | 21190 |
| 9 | 71260 |
| 10 | 238432 |
| 11 | 794914 |
| 12 | 2643352 |
| 13 | 8773684 |
| 14 | 29082010 |
| 15 | 96303640 |
| 16 | 318678388 |
| 17 | 1053993646 |
| 18 | 3484654468 |
| 19 | 11517602176 |
| 20 | 38060746390 |
| 21 | 125756057260 |
| 22 | 415464635392 |
| 23 | 1372477613794 |
| 24 | 4533688494712 |
| 25 | 14975452784164 |
| 26 | 49464657237610 |
[2,10,40,148,526,1828,6256,21190,71260,238432, 794914,2643352,8773684,29082010,96303640, 318678388,1053993646,3484654468,11517602176, 38060746390,125756057260,415464635392, 1372477613794,4533688494712,14975452784164, 49464657237610] |