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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 28 |
| 4 | 118 |
| 5 | 469 |
| 6 | 2039 |
| 7 | 8559 |
| 8 | 37909 |
| 9 | 164062 |
| 10 | 735698 |
| 11 | 3246436 |
| 12 | 14688132 |
| 13 | 65690534 |
| 14 | 299227510 |
| 15 | 1351439955 |
| 16 | 6188946223 |
| 17 | 28161550486 |
| 18 | 129528141204 |
| 19 | 592866204918 |
| 20 | 2736746791312 |
| 21 | 12585998174974 |
| 22 | 58276845530802 |
| 23 | 269058921980442 |
| 24 | 1249107763866352 |
| 25 | 5785962784369466 |
| 26 | 26923056650212598 |
| 27 | 125058263384130622 |
[1,2,8,28,118,469,2039,8559,37909,164062,735698, 3246436,14688132,65690534,299227510,1351439955, 6188946223,28161550486,129528141204,592866204918, 2736746791312,12585998174974,58276845530802, 269058921980442,1249107763866352,5785962784369466, 26923056650212598,125058263384130622] |