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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 16 |
| 4 | 45 |
| 5 | 120 |
| 6 | 333 |
| 7 | 928 |
| 8 | 2613 |
| 9 | 7400 |
| 10 | 21053 |
| 11 | 60080 |
| 12 | 171845 |
| 13 | 492280 |
| 14 | 1411789 |
| 15 | 4051904 |
| 16 | 11635413 |
| 17 | 33424648 |
| 18 | 96042845 |
| 19 | 276020944 |
| 20 | 793366629 |
| 21 | 2280573208 |
| 22 | 6556026349 |
| 23 | 18847591392 |
| 24 | 54185601013 |
| 25 | 155783294760 |
| 26 | 447882509949 |
[1,7,16,45,120,333,928,2613,7400,21053,60080, 171845,492280,1411789,4051904,11635413,33424648, 96042845,276020944,793366629,2280573208, 6556026349,18847591392,54185601013,155783294760, 447882509949] |