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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 60 |
| 5 | 226 |
| 6 | 894 |
| 7 | 3568 |
| 8 | 14593 |
| 9 | 60774 |
| 10 | 255405 |
| 11 | 1088287 |
| 12 | 4680842 |
| 13 | 20270594 |
| 14 | 88477666 |
| 15 | 388406999 |
| 16 | 1713712621 |
| 17 | 7599271318 |
| 18 | 33835186549 |
| 19 | 151220870639 |
| 20 | 678235333756 |
| 21 | 3051277234793 |
| 22 | 13766822178955 |
| 23 | 62276897969003 |
| 24 | 282398247564030 |
| 25 | 1283429063755581 |
| 26 | 5844908741209452 |
| 27 | 26669699058543416 |
[1,2,5,17,60,226,894,3568,14593,60774,255405, 1088287,4680842,20270594,88477666,388406999, 1713712621,7599271318,33835186549,151220870639, 678235333756,3051277234793,13766822178955, 62276897969003,282398247564030,1283429063755581, 5844908741209452,26669699058543416] |