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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 49 |
| 6 | 171 |
| 7 | 609 |
| 8 | 2256 |
| 9 | 8551 |
| 10 | 33397 |
| 11 | 131427 |
| 12 | 529260 |
| 13 | 2149049 |
| 14 | 8851768 |
| 15 | 36730319 |
| 16 | 154130790 |
| 17 | 650143287 |
| 18 | 2767497613 |
| 19 | 11832774631 |
| 20 | 50953284486 |
| 21 | 220254234487 |
| 22 | 957671050740 |
| 23 | 4177306152161 |
| 24 | 18311313390468 |
| 25 | 80489613677085 |
| 26 | 355279416601419 |
| 27 | 1571992334010585 |
| 28 | 6980467436390932 |
[1,1,2,5,16,49,171,609,2256,8551,33397,131427, 529260,2149049,8851768,36730319,154130790, 650143287,2767497613,11832774631,50953284486, 220254234487,957671050740,4177306152161, 18311313390468,80489613677085,355279416601419, 1571992334010585,6980467436390932] |