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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 36 |
| 5 | 136 |
| 6 | 532 |
| 7 | 2139 |
| 8 | 8796 |
| 9 | 36859 |
| 10 | 156946 |
| 11 | 677514 |
| 12 | 2959669 |
| 13 | 13063493 |
| 14 | 58184838 |
| 15 | 261230814 |
| 16 | 1181144792 |
| 17 | 5374078726 |
| 18 | 24588562675 |
| 19 | 113067256235 |
| 20 | 522270436044 |
| 21 | 2422244159067 |
| 22 | 11275548912967 |
| 23 | 52663412854571 |
[0,1,3,10,36,136,532,2139,8796,36859,156946, 677514,2959669,13063493,58184838,261230814, 1181144792,5374078726,24588562675,113067256235, 522270436044,2422244159067,11275548912967, 52663412854571] |