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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 100 |
| 6 | 370 |
| 7 | 1372 |
| 8 | 5290 |
| 9 | 20266 |
| 10 | 80361 |
| 11 | 321735 |
| 12 | 1307984 |
| 13 | 5335667 |
| 14 | 22024808 |
| 15 | 91659114 |
| 16 | 384509857 |
| 17 | 1620023737 |
| 18 | 6864307125 |
| 19 | 29248903041 |
| 20 | 125269708719 |
| 21 | 538502958487 |
| 22 | 2323193194405 |
| 23 | 10060821504853 |
| 24 | 43727466779310 |
| 25 | 190618286246040 |
| 26 | 833147784737097 |
| 27 | 3651348013005285 |
| 28 | 16045299842617819 |
[1,1,3,9,31,100,370,1372,5290,20266,80361,321735, 1307984,5335667,22024808,91659114,384509857, 1620023737,6864307125,29248903041,125269708719, 538502958487,2323193194405,10060821504853, 43727466779310,190618286246040,833147784737097, 3651348013005285,16045299842617819] |