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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 76 |
| 4 | 357 |
| 5 | 1662 |
| 6 | 8203 |
| 7 | 36609 |
| 8 | 169800 |
| 9 | 788024 |
| 10 | 3586350 |
| 11 | 15948147 |
| 12 | 73761986 |
| 13 | 324147729 |
| 14 | 1454796651 |
| 15 | 6544916640 |
| 16 | 28902107643 |
| 17 | 126842754933 |
| 18 | 567156315794 |
| 19 | 2468434955040 |
| 20 | 10893525305088 |
| 21 | 47854663427104 |
| 22 | 208582052412240 |
| 23 | 905923236202737 |
| 24 | 3975385018556868 |
| 25 | 17200981327476354 |
| 26 | 74619131550054048 |
| 27 | 323976744392754994 |
| 28 | 1400917964875907424 |
| 29 | 6031485491299656747 |
[1,3,15,76,357,1662,8203,36609,169800,788024, 3586350,15948147,73761986,324147729,1454796651, 6544916640,28902107643,126842754933,567156315794, 2468434955040,10893525305088,47854663427104, 208582052412240,905923236202737,3975385018556868, 17200981327476354,74619131550054048, 323976744392754994,1400917964875907424, 6031485491299656747] |