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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 1 |
| 4 | 10 |
| 5 | 12 |
| 6 | 70 |
| 7 | 139 |
| 8 | 607 |
| 9 | 1602 |
| 10 | 6152 |
| 11 | 18933 |
| 12 | 69198 |
| 13 | 231382 |
| 14 | 835638 |
| 15 | 2924153 |
| 16 | 10602298 |
| 17 | 38116310 |
| 18 | 139479988 |
| 19 | 510483372 |
| 20 | 1887183843 |
| 21 | 6997718116 |
| 22 | 26119506819 |
| 23 | 97854304825 |
| 24 | 368400345109 |
| 25 | 1391981776521 |
| 26 | 5280261360181 |
| 27 | 20096390417468 |
| 28 | 76739852267440 |
| 29 | 293910546549621 |
| 30 | 1128904523397628 |
| 31 | 4347615932984721 |
[1,0,2,1,10,12,70,139,607,1602,6152,18933,69198, 231382,835638,2924153,10602298,38116310,139479988, 510483372,1887183843,6997718116,26119506819, 97854304825,368400345109,1391981776521, 5280261360181,20096390417468,76739852267440, 293910546549621,1128904523397628,4347615932984721] |