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| n | a(n) |
|---|---|
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 9 |
| 7 | 22 |
| 8 | 54 |
| 9 | 139 |
| 10 | 346 |
| 11 | 892 |
| 12 | 2290 |
| 13 | 5945 |
| 14 | 15465 |
| 15 | 40527 |
| 16 | 106308 |
| 17 | 280629 |
| 18 | 742107 |
| 19 | 1969394 |
| 20 | 5239322 |
| 21 | 13980900 |
| 22 | 37368692 |
| 23 | 100157418 |
| 24 | 268900827 |
| 25 | 723400570 |
| 26 | 1949440608 |
| 27 | 5262932344 |
| 28 | 14227803491 |
| 29 | 38529294292 |
| 30 | 104473993774 |
| 31 | 283672750693 |
| 32 | 771229441388 |
[0,1,1,4,9,22,54,139,346,892,2290,5945,15465, 40527,106308,280629,742107,1969394,5239322, 13980900,37368692,100157418,268900827,723400570, 1949440608,5262932344,14227803491,38529294292, 104473993774,283672750693,771229441388] |