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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 23 |
| 7 | 54 |
| 8 | 131 |
| 9 | 318 |
| 10 | 781 |
| 11 | 1937 |
| 12 | 4841 |
| 13 | 12175 |
| 14 | 30791 |
| 15 | 78254 |
| 16 | 199721 |
| 17 | 511640 |
| 18 | 1315064 |
| 19 | 3390147 |
| 20 | 8762929 |
| 21 | 22705350 |
| 22 | 58960248 |
| 23 | 153411988 |
| 24 | 399903630 |
| 25 | 1044199306 |
| 26 | 2730780816 |
| 27 | 7151800337 |
| 28 | 18755305334 |
| 29 | 49246220422 |
| 30 | 129456991053 |
| 31 | 340682085365 |
[1,1,2,4,10,23,54,131,318,781,1937,4841,12175, 30791,78254,199721,511640,1315064,3390147,8762929, 22705350,58960248,153411988,399903630,1044199306, 2730780816,7151800337,18755305334,49246220422, 129456991053,340682085365] |