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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 37 |
| 6 | 112 |
| 7 | 352 |
| 8 | 1136 |
| 9 | 3742 |
| 10 | 12529 |
| 11 | 42513 |
| 12 | 145868 |
| 13 | 505234 |
| 14 | 1764157 |
| 15 | 6203370 |
| 16 | 21947490 |
| 17 | 78072209 |
| 18 | 279062937 |
| 19 | 1001803617 |
| 20 | 3610366030 |
| 21 | 13057141261 |
| 22 | 47373444827 |
| 23 | 172381857939 |
| 24 | 628944880851 |
| 25 | 2300410562946 |
| 26 | 8433110899963 |
| 27 | 30980398420830 |
| 28 | 114034887644860 |
[1,1,2,5,13,37,112,352,1136,3742,12529,42513, 145868,505234,1764157,6203370,21947490,78072209, 279062937,1001803617,3610366030,13057141261, 47373444827,172381857939,628944880851, 2300410562946,8433110899963,30980398420830, 114034887644860] |