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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 52 |
| 5 | 247 |
| 6 | 1226 |
| 7 | 6299 |
| 8 | 33209 |
| 9 | 178618 |
| 10 | 976296 |
| 11 | 5407384 |
| 12 | 30283120 |
| 13 | 171196956 |
| 14 | 975662480 |
| 15 | 5599508648 |
| 16 | 32334837886 |
| 17 | 187737500013 |
| 18 | 1095295264857 |
| 19 | 6417886638389 |
| 20 | 37752602033079 |
| 21 | 222861754454841 |
| 22 | 1319834477009635 |
| 23 | 7839314017612273 |
| 24 | 46688045740233741 |
[1,1,3,12,52,247,1226,6299,33209,178618,976296, 5407384,30283120,171196956,975662480,5599508648, 32334837886,187737500013,1095295264857, 6417886638389,37752602033079,222861754454841, 1319834477009635,7839314017612273, 46688045740233741] |