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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 39 |
| 4 | 182 |
| 5 | 852 |
| 6 | 4108 |
| 7 | 19823 |
| 8 | 96863 |
| 9 | 473880 |
| 10 | 2332888 |
| 11 | 11496804 |
| 12 | 56851680 |
| 13 | 281377414 |
| 14 | 1395432127 |
| 15 | 6925190403 |
| 16 | 34411294573 |
| 17 | 171084261164 |
| 18 | 851292169963 |
| 19 | 4237755958166 |
| 20 | 21107672581679 |
| 21 | 105170417325035 |
| 22 | 524231455105750 |
| 23 | 2613788813959797 |
| 24 | 13036097656965666 |
| 25 | 65030749014857713 |
| 26 | 324479983088294808 |
[1,2,9,39,182,852,4108,19823,96863,473880,2332888, 11496804,56851680,281377414,1395432127,6925190403, 34411294573,171084261164,851292169963, 4237755958166,21107672581679,105170417325035, 524231455105750,2613788813959797, 13036097656965666,65030749014857713, 324479983088294808] |