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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 10 |
| 4 | 49 |
| 5 | 151 |
| 6 | 532 |
| 7 | 2353 |
| 8 | 9745 |
| 9 | 37675 |
| 10 | 150851 |
| 11 | 624603 |
| 12 | 2561476 |
| 13 | 10426625 |
| 14 | 42800031 |
| 15 | 176797510 |
| 16 | 730069649 |
| 17 | 3016004001 |
| 18 | 12492387775 |
| 19 | 51845882845 |
| 20 | 215363387699 |
| 21 | 895504027855 |
| 22 | 3728271696139 |
| 23 | 15538300424315 |
| 24 | 64812978200068 |
| 25 | 270565786871401 |
| 26 | 1130394586039421 |
[1,1,1,10,49,151,532,2353,9745,37675,150851, 624603,2561476,10426625,42800031,176797510, 730069649,3016004001,12492387775,51845882845, 215363387699,895504027855,3728271696139, 15538300424315,64812978200068,270565786871401, 1130394586039421] |