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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 10 |
| 6 | 28 |
| 7 | 82 |
| 8 | 256 |
| 9 | 808 |
| 10 | 2617 |
| 11 | 8566 |
| 12 | 28447 |
| 13 | 95416 |
| 14 | 323002 |
| 15 | 1101724 |
| 16 | 3783769 |
| 17 | 13071556 |
| 18 | 45396925 |
| 19 | 158400937 |
| 20 | 555035695 |
| 21 | 1952238598 |
| 22 | 6890367190 |
| 23 | 24395779840 |
| 24 | 86623201930 |
| 25 | 308388736639 |
| 26 | 1100569819672 |
| 27 | 3936511575349 |
| 28 | 14109420968044 |
| 29 | 50669532081790 |
| 30 | 182291946385519 |
| 31 | 656930486625718 |
| 32 | 2371133950246495 |
[1,1,1,4,10,28,82,256,808,2617,8566,28447,95416, 323002,1101724,3783769,13071556,45396925, 158400937,555035695,1952238598,6890367190, 24395779840,86623201930,308388736639, 1100569819672,3936511575349,14109420968044, 50669532081790,182291946385519,656930486625718, 2371133950246495] |