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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 32 |
| 5 | 112 |
| 6 | 416 |
| 7 | 1600 |
| 8 | 6303 |
| 9 | 25287 |
| 10 | 103015 |
| 11 | 425429 |
| 12 | 1777767 |
| 13 | 7500273 |
| 14 | 31915140 |
| 15 | 136814101 |
| 16 | 590457109 |
| 17 | 2563483906 |
| 18 | 11188928245 |
| 19 | 49072703877 |
| 20 | 216169809953 |
| 21 | 956076808622 |
| 22 | 4244091355887 |
| 23 | 18903499430285 |
| 24 | 84460316766813 |
| 25 | 378457183512630 |
| 26 | 1700378927500223 |
| 27 | 7658769324015511 |
| 28 | 34576775876824113 |
[1,1,3,9,32,112,416,1600,6303,25287,103015,425429, 1777767,7500273,31915140,136814101,590457109, 2563483906,11188928245,49072703877,216169809953, 956076808622,4244091355887,18903499430285, 84460316766813,378457183512630,1700378927500223, 7658769324015511,34576775876824113] |