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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 108 |
| 5 | 463 |
| 6 | 2053 |
| 7 | 9276 |
| 8 | 42580 |
| 9 | 197621 |
| 10 | 925797 |
| 11 | 4367991 |
| 12 | 20729923 |
| 13 | 98861972 |
| 14 | 473396633 |
| 15 | 2274642969 |
| 16 | 10962025393 |
| 17 | 52963617803 |
| 18 | 256467666679 |
| 19 | 1244348111778 |
| 20 | 6047914292651 |
| 21 | 29440250497638 |
| 22 | 143509626245943 |
| 23 | 700428228300365 |
| 24 | 3422456235121489 |
| 25 | 16740168981550789 |
| 26 | 81957796371148728 |
[1,2,7,26,108,463,2053,9276,42580,197621,925797, 4367991,20729923,98861972,473396633,2274642969, 10962025393,52963617803,256467666679, 1244348111778,6047914292651,29440250497638, 143509626245943,700428228300365,3422456235121489, 16740168981550789,81957796371148728] |