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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 23 |
| 4 | 98 |
| 5 | 361 |
| 6 | 1641 |
| 7 | 6456 |
| 8 | 29975 |
| 9 | 122797 |
| 10 | 578538 |
| 11 | 2430398 |
| 12 | 11586047 |
| 13 | 49532072 |
| 14 | 238059400 |
| 15 | 1031522751 |
| 16 | 4985820454 |
| 17 | 21833680533 |
| 18 | 105999201265 |
| 19 | 468105465078 |
| 20 | 2280838830949 |
| 21 | 10141757366336 |
| 22 | 49561550196373 |
| 23 | 221645646042901 |
| 24 | 1085765734275864 |
| 25 | 4879481984566974 |
| 26 | 23951166794986119 |
| 27 | 108090536459660901 |
[1,2,7,23,98,361,1641,6456,29975,122797,578538, 2430398,11586047,49532072,238059400,1031522751, 4985820454,21833680533,105999201265,468105465078, 2280838830949,10141757366336,49561550196373, 221645646042901,1085765734275864,4879481984566974, 23951166794986119,108090536459660901] |