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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 79 |
| 6 | 308 |
| 7 | 1230 |
| 8 | 5122 |
| 9 | 21917 |
| 10 | 95429 |
| 11 | 420388 |
| 12 | 1874468 |
| 13 | 8451916 |
| 14 | 38469785 |
| 15 | 176364014 |
| 16 | 813412342 |
| 17 | 3772468146 |
| 18 | 17586034802 |
| 19 | 82346756679 |
| 20 | 387060294933 |
| 21 | 1825485662648 |
| 22 | 8636347518082 |
| 23 | 40975310094819 |
| 24 | 194907689107949 |
| 25 | 929256234842093 |
| 26 | 4439720262125077 |
| 27 | 21253098983214205 |
| 28 | 101922815438706386 |
[1,1,2,6,21,79,308,1230,5122,21917,95429,420388, 1874468,8451916,38469785,176364014,813412342, 3772468146,17586034802,82346756679,387060294933, 1825485662648,8636347518082,40975310094819, 194907689107949,929256234842093,4439720262125077, 21253098983214205,101922815438706386] |