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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 105 |
| 5 | 444 |
| 6 | 1947 |
| 7 | 8711 |
| 8 | 39591 |
| 9 | 182324 |
| 10 | 848227 |
| 11 | 3976086 |
| 12 | 18761532 |
| 13 | 89032134 |
| 14 | 424423410 |
| 15 | 2031081206 |
| 16 | 9753336307 |
| 17 | 46975045125 |
| 18 | 226821209031 |
| 19 | 1097703227863 |
| 20 | 5323162897579 |
| 21 | 25860225840988 |
| 22 | 125831368964770 |
| 23 | 613165370055901 |
| 24 | 2991836251485650 |
| 25 | 14615473211851948 |
| 26 | 71475761295702573 |
[1,2,7,26,105,444,1947,8711,39591,182324,848227, 3976086,18761532,89032134,424423410,2031081206, 9753336307,46975045125,226821209031,1097703227863, 5323162897579,25860225840988,125831368964770, 613165370055901,2991836251485650, 14615473211851948,71475761295702573] |