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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 6 |
| 3 | 11 |
| 4 | 20 |
| 5 | 60 |
| 6 | 78 |
| 7 | 157 |
| 8 | 314 |
| 9 | 624 |
| 10 | 1245 |
| 11 | 3736 |
| 12 | 4982 |
| 13 | 9962 |
| 14 | 19920 |
| 15 | 39844 |
| 16 | 79688 |
| 17 | 239046 |
| 18 | 318725 |
| 19 | 956194 |
| 20 | 1912371 |
| 21 | 2549834 |
| 22 | 5099650 |
| 23 | 15298984 |
| 24 | 20398664 |
| 25 | 40797327 |
| 26 | 81594626 |
| 27 | 163189197 |
| 28 | 326378284 |
| 29 | 979135127 |
| 30 | 1305513583 |
| 31 | 2611027094 |
| 32 | 5222054081 |
| 33 | 10444108051 |
[1,3,6,11,20,60,78,157,314,624,1245,3736,4982, 9962,19920,39844,79688,239046,318725,956194, 1912371,2549834,5099650,15298984,20398664, 40797327,81594626,163189197,326378284,979135127, 1305513583,2611027094,5222054081,10444108051] |