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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 107 |
| 5 | 436 |
| 6 | 1988 |
| 7 | 8626 |
| 8 | 40383 |
| 9 | 181774 |
| 10 | 863053 |
| 11 | 3976233 |
| 12 | 19049695 |
| 13 | 89148987 |
| 14 | 429832065 |
| 15 | 2033938473 |
| 16 | 9853400726 |
| 17 | 47009046208 |
| 18 | 228573689009 |
| 19 | 1097345190023 |
| 20 | 5351235961000 |
| 21 | 25817379702471 |
| 22 | 126197005063640 |
| 23 | 611264042341269 |
| 24 | 2993732482130413 |
| 25 | 14547976910603581 |
| 26 | 71367049022673631 |
[1,2,7,25,107,436,1988,8626,40383,181774,863053, 3976233,19049695,89148987,429832065,2033938473, 9853400726,47009046208,228573689009,1097345190023, 5351235961000,25817379702471,126197005063640, 611264042341269,2993732482130413, 14547976910603581,71367049022673631] |