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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 39 |
| 6 | 161 |
| 7 | 699 |
| 8 | 3135 |
| 9 | 14427 |
| 10 | 67716 |
| 11 | 322959 |
| 12 | 1560585 |
| 13 | 7624007 |
| 14 | 37593476 |
| 15 | 186856061 |
| 16 | 935214523 |
| 17 | 4709265692 |
| 18 | 23841104525 |
| 19 | 121275951719 |
| 20 | 619558165489 |
| 21 | 3177346503440 |
| 22 | 16351749778167 |
| 23 | 84419824808865 |
| 24 | 437105510426235 |
| 25 | 2269266695980449 |
| 26 | 11810014285000263 |
| 27 | 61602685079710638 |
[1,1,3,10,39,161,699,3135,14427,67716,322959, 1560585,7624007,37593476,186856061,935214523, 4709265692,23841104525,121275951719,619558165489, 3177346503440,16351749778167,84419824808865, 437105510426235,2269266695980449, 11810014285000263,61602685079710638] |