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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 30 |
| 3 | 150 |
| 4 | 726 |
| 5 | 3534 |
| 6 | 16926 |
| 7 | 81390 |
| 8 | 387966 |
| 9 | 1853886 |
| 10 | 8809878 |
| 11 | 41934150 |
| 12 | 198842742 |
| 13 | 943974510 |
| 14 | 4468911678 |
| 15 | 21175146054 |
| 16 | 100121875974 |
| 17 | 473730252102 |
| 18 | 2237723684094 |
| 19 | 10576033219614 |
| 20 | 49917327838734 |
| 21 | 235710090502158 |
| 22 | 1111781983442406 |
| 23 | 5245988215191414 |
| 24 | 24730180885580790 |
| 25 | 116618841700433358 |
| 26 | 549493796867100942 |
| 27 | 2589874864863200574 |
| 28 | 12198184788179866902 |
| 29 | 57466913094951837030 |
| 30 | 270569905525454674614 |
[1,6,30,150,726,3534,16926,81390,387966,1853886, 8809878,41934150,198842742,943974510,4468911678, 21175146054,100121875974,473730252102, 2237723684094,10576033219614,49917327838734, 235710090502158,1111781983442406,5245988215191414, 24730180885580790,116618841700433358, 549493796867100942,2589874864863200574, 12198184788179866902,57466913094951837030, 270569905525454674614] |