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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 17 |
| 4 | 68 |
| 5 | 262 |
| 6 | 898 |
| 7 | 3415 |
| 8 | 12665 |
| 9 | 48273 |
| 10 | 185597 |
| 11 | 705894 |
| 12 | 2710318 |
| 13 | 10414884 |
| 14 | 40204048 |
| 15 | 155766007 |
| 16 | 603806026 |
| 17 | 2345327257 |
| 18 | 9121945554 |
| 19 | 35535598716 |
| 20 | 138649731701 |
| 21 | 541549508686 |
| 22 | 2117490125861 |
| 23 | 8287250061067 |
| 24 | 32463187726182 |
[1,1,6,17,68,262,898,3415,12665,48273,185597, 705894,2710318,10414884,40204048,155766007, 603806026,2345327257,9121945554,35535598716, 138649731701,541549508686,2117490125861, 8287250061067,32463187726182] |