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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 42 |
| 5 | 196 |
| 6 | 644 |
| 7 | 2116 |
| 8 | 6854 |
| 9 | 22201 |
| 10 | 78076 |
| 11 | 274576 |
| 12 | 937960 |
| 13 | 3204100 |
| 14 | 10890360 |
| 15 | 37015056 |
| 16 | 126620208 |
| 17 | 433139344 |
| 18 | 1480295124 |
| 19 | 5059050129 |
| 20 | 17273618712 |
| 21 | 58979036736 |
| 22 | 201463380504 |
| 23 | 688168134481 |
| 24 | 2350844113032 |
| 25 | 8030694487104 |
[1,3,9,42,196,644,2116,6854,22201,78076,274576, 937960,3204100,10890360,37015056,126620208, 433139344,1480295124,5059050129,17273618712, 58979036736,201463380504,688168134481, 2350844113032,8030694487104] |