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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 23 |
| 4 | 92 |
| 5 | 380 |
| 6 | 1630 |
| 7 | 7195 |
| 8 | 32200 |
| 9 | 145918 |
| 10 | 669934 |
| 11 | 3102919 |
| 12 | 14466977 |
| 13 | 67898824 |
| 14 | 320478114 |
| 15 | 1519165126 |
| 16 | 7229743620 |
| 17 | 34533144636 |
| 18 | 165451888585 |
| 19 | 794799824624 |
| 20 | 3827600444914 |
| 21 | 18473906584806 |
| 22 | 89336464112058 |
| 23 | 432785951713789 |
| 24 | 2100067566081285 |
| 25 | 10205439175820345 |
| 26 | 49660624022681468 |
| 27 | 241956081389224856 |
[1,2,6,23,92,380,1630,7195,32200,145918,669934, 3102919,14466977,67898824,320478114,1519165126, 7229743620,34533144636,165451888585,794799824624, 3827600444914,18473906584806,89336464112058, 432785951713789,2100067566081285, 10205439175820345,49660624022681468, 241956081389224856] |