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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 32 |
| 6 | 107 |
| 7 | 303 |
| 8 | 1129 |
| 9 | 3434 |
| 10 | 13071 |
| 11 | 42148 |
| 12 | 167993 |
| 13 | 561875 |
| 14 | 2267904 |
| 15 | 7834604 |
| 16 | 32442310 |
| 17 | 114598028 |
| 18 | 478406714 |
| 19 | 1725209229 |
| 20 | 7320631607 |
| 21 | 26799600927 |
| 22 | 114360856625 |
| 23 | 424737947485 |
| 24 | 1833141175429 |
| 25 | 6882799867886 |
| 26 | 29828067212451 |
| 27 | 113195225162010 |
| 28 | 494672858704167 |
| 29 | 1892803590856411 |
[1,1,2,4,13,32,107,303,1129,3434,13071,42148, 167993,561875,2267904,7834604,32442310,114598028, 478406714,1725209229,7320631607,26799600927, 114360856625,424737947485,1833141175429, 6882799867886,29828067212451,113195225162010, 494672858704167,1892803590856411] |