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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 25 |
| 4 | 111 |
| 5 | 461 |
| 6 | 2035 |
| 7 | 8823 |
| 8 | 39053 |
| 9 | 172355 |
| 10 | 767425 |
| 11 | 3420017 |
| 12 | 15311495 |
| 13 | 68665323 |
| 14 | 308805403 |
| 15 | 1391091909 |
| 16 | 6278869703 |
| 17 | 28381760049 |
| 18 | 128482271031 |
| 19 | 582346682067 |
| 20 | 2642616002605 |
| 21 | 12004291295381 |
| 22 | 54583533395613 |
| 23 | 248409301882015 |
[1,7,25,111,461,2035,8823,39053,172355,767425, 3420017,15311495,68665323,308805403,1391091909, 6278869703,28381760049,128482271031,582346682067, 2642616002605,12004291295381,54583533395613, 248409301882015] |