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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 15 |
| 7 | 34 |
| 8 | 78 |
| 9 | 191 |
| 10 | 493 |
| 11 | 1324 |
| 12 | 3626 |
| 13 | 10032 |
| 14 | 27808 |
| 15 | 77045 |
| 16 | 213273 |
| 17 | 590475 |
| 18 | 1637117 |
| 19 | 4550836 |
| 20 | 12692866 |
| 21 | 35532414 |
| 22 | 99830094 |
| 23 | 281412535 |
| 24 | 795601139 |
| 25 | 2254966896 |
| 26 | 6405076658 |
| 27 | 18227600051 |
| 28 | 51960277037 |
| 29 | 148352016215 |
| 30 | 424186720927 |
| 31 | 1214602291322 |
[0,0,0,1,3,7,15,34,78,191,493,1324,3626,10032, 27808,77045,213273,590475,1637117,4550836, 12692866,35532414,99830094,281412535,795601139, 2254966896,6405076658,18227600051,51960277037, 148352016215,424186720927,1214602291322] |