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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 1 |
| 6 | 5 |
| 7 | 19 |
| 8 | 65 |
| 9 | 179 |
| 10 | 567 |
| 11 | 1971 |
| 12 | 7188 |
| 13 | 24104 |
| 14 | 86560 |
| 15 | 307758 |
| 16 | 1093010 |
| 17 | 3680499 |
| 18 | 12984253 |
| 19 | 44872804 |
| 20 | 155894872 |
| 21 | 524533909 |
| 22 | 1798853267 |
| 23 | 6095276268 |
| 24 | 20640244000 |
| 25 | 68424020576 |
| 26 | 228663331673 |
| 27 | 756885973017 |
| 28 | 2497335148084 |
| 29 | 8126657372315 |
| 30 | 26483584838833 |
| 31 | 85638964006761 |
| 32 | 275736953129009 |
[1,1,1,2,1,5,19,65,179,567,1971,7188,24104,86560, 307758,1093010,3680499,12984253,44872804, 155894872,524533909,1798853267,6095276268, 20640244000,68424020576,228663331673,756885973017, 2497335148084,8126657372315,26483584838833, 85638964006761,275736953129009] |