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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 36 |
| 4 | 164 |
| 5 | 748 |
| 6 | 3412 |
| 7 | 15564 |
| 8 | 70996 |
| 9 | 323852 |
| 10 | 1477268 |
| 11 | 6738636 |
| 12 | 30738644 |
| 13 | 140215948 |
| 14 | 639602452 |
| 15 | 2917580364 |
| 16 | 13308696916 |
| 17 | 60708323852 |
| 18 | 276924225428 |
| 19 | 1263204479436 |
| 20 | 5762173946324 |
| 21 | 26284460772748 |
| 22 | 119897955971092 |
| 23 | 546920858309964 |
| 24 | 2494808379607636 |
| 25 | 11380200181418252 |
[1,2,8,36,164,748,3412,15564,70996,323852,1477268, 6738636,30738644,140215948,639602452,2917580364, 13308696916,60708323852,276924225428, 1263204479436,5762173946324,26284460772748, 119897955971092,546920858309964,2494808379607636, 11380200181418252] |