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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 18 |
| 7 | 40 |
| 8 | 100 |
| 9 | 256 |
| 10 | 705 |
| 11 | 2057 |
| 12 | 6370 |
| 13 | 20803 |
| 14 | 71725 |
| 15 | 259678 |
| 16 | 985244 |
| 17 | 3905022 |
| 18 | 16124936 |
| 19 | 69188809 |
| 20 | 307765510 |
| 21 | 1416146859 |
| 22 | 6727549181 |
| 23 | 32938379216 |
| 24 | 165942445714 |
| 25 | 859020421012 |
| 26 | 4563322971706 |
| 27 | 24847598243116 |
| 28 | 138533012486423 |
| 29 | 790075521708603 |
| 30 | 4605183081182354 |
[0,1,2,4,8,18,40,100,256,705,2057,6370,20803, 71725,259678,985244,3905022,16124936,69188809, 307765510,1416146859,6727549181,32938379216, 165942445714,859020421012,4563322971706, 24847598243116,138533012486423,790075521708603, 4605183081182354] |