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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 86 |
| 5 | 316 |
| 6 | 1189 |
| 7 | 4562 |
| 8 | 17796 |
| 9 | 70398 |
| 10 | 281812 |
| 11 | 1139658 |
| 12 | 4649402 |
| 13 | 19112962 |
| 14 | 79096155 |
| 15 | 329258424 |
| 16 | 1377798890 |
| 17 | 5792421108 |
| 18 | 24454224310 |
| 19 | 103631241912 |
| 20 | 440674939192 |
| 21 | 1879769835968 |
| 22 | 8041447249926 |
| 23 | 34490981798188 |
| 24 | 148295899087660 |
| 25 | 639036278210420 |
[1,2,7,24,86,316,1189,4562,17796,70398,281812, 1139658,4649402,19112962,79096155,329258424, 1377798890,5792421108,24454224310,103631241912, 440674939192,1879769835968,8041447249926, 34490981798188,148295899087660,639036278210420] |