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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 5 |
| 8 | 11 |
| 9 | 37 |
| 10 | 166 |
| 11 | 1237 |
| 12 | 19749 |
| 13 | 936055 |
| 14 | 179814643 |
| 15 | 240916863586 |
| 16 | 4926183534613279 |
| 17 | 4654499108310829164143 |
| 18 | 838133896191338105830469104443 |
| 19 | 201943518452400520392903690464302135967495 |
| 20 | 994814736615560793049792416556718062880283217474796953454 |
[1,1,1,1,2,3,5,11,37,166,1237,19749,936055, 179814643,240916863586,4926183534613279, 4654499108310829164143, 838133896191338105830469104443, 201943518452400520392903690464302135967495, 99481473661556079304979241655671806288028321747479\ 6953454] |