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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 35 |
| 7 | 107 |
| 8 | 257 |
| 9 | 585 |
| 10 | 1423 |
| 11 | 3505 |
| 12 | 8633 |
| 13 | 21808 |
| 14 | 55437 |
| 15 | 138452 |
| 16 | 342488 |
| 17 | 850499 |
| 18 | 2117997 |
| 19 | 5272078 |
| 20 | 13136438 |
| 21 | 32770428 |
| 22 | 81689634 |
| 23 | 203427274 |
| 24 | 506595905 |
| 25 | 1261968342 |
| 26 | 3143705888 |
| 27 | 7831363780 |
| 28 | 19510741790 |
| 29 | 48608257139 |
| 30 | 121091284415 |
[1,1,2,4,10,35,107,257,585,1423,3505,8633,21808, 55437,138452,342488,850499,2117997,5272078, 13136438,32770428,81689634,203427274,506595905, 1261968342,3143705888,7831363780,19510741790, 48608257139,121091284415] |