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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 31 |
| 6 | 91 |
| 7 | 288 |
| 8 | 940 |
| 9 | 3099 |
| 10 | 10607 |
| 11 | 37862 |
| 12 | 134767 |
| 13 | 490159 |
| 14 | 1826803 |
| 15 | 6870465 |
| 16 | 26029551 |
| 17 | 100186211 |
| 18 | 390244176 |
| 19 | 1525584938 |
| 20 | 6022917327 |
| 21 | 24022355598 |
| 22 | 96252798082 |
| 23 | 387763662137 |
| 24 | 1574666317612 |
| 25 | 6428731348930 |
| 26 | 26336898559556 |
| 27 | 108517986685355 |
| 28 | 449469203453607 |
| 29 | 1867377245920794 |
[1,1,2,4,12,31,91,288,940,3099,10607,37862,134767, 490159,1826803,6870465,26029551,100186211, 390244176,1525584938,6022917327,24022355598, 96252798082,387763662137,1574666317612, 6428731348930,26336898559556,108517986685355, 449469203453607,1867377245920794] |