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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 7 |
| 6 | 19 |
| 7 | 39 |
| 8 | 120 |
| 9 | 411 |
| 10 | 1310 |
| 11 | 3862 |
| 12 | 11059 |
| 13 | 31849 |
| 14 | 89615 |
| 15 | 247305 |
| 16 | 674579 |
| 17 | 1812940 |
| 18 | 4806211 |
| 19 | 12576930 |
| 20 | 32509641 |
| 21 | 83052304 |
| 22 | 209808493 |
| 23 | 524424707 |
| 24 | 1297623584 |
| 25 | 3179903180 |
| 26 | 7721053410 |
| 27 | 18582920108 |
| 28 | 44349211490 |
| 29 | 104989527861 |
| 30 | 246624184465 |
| 31 | 575024282279 |
[1,1,2,2,7,19,39,120,411,1310,3862,11059,31849, 89615,247305,674579,1812940,4806211,12576930, 32509641,83052304,209808493,524424707,1297623584, 3179903180,7721053410,18582920108,44349211490, 104989527861,246624184465,575024282279] |