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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 36 |
| 7 | 102 |
| 8 | 299 |
| 9 | 892 |
| 10 | 2713 |
| 11 | 8364 |
| 12 | 26108 |
| 13 | 82310 |
| 14 | 261804 |
| 15 | 838961 |
| 16 | 2706336 |
| 17 | 8780725 |
| 18 | 28636157 |
| 19 | 93818641 |
| 20 | 308641277 |
| 21 | 1019140129 |
| 22 | 3376604826 |
| 23 | 11221805968 |
| 24 | 37399728251 |
| 25 | 124967677989 |
| 26 | 418564867751 |
| 27 | 1405030366113 |
| 28 | 4726036692421 |
| 29 | 15927027834163 |
| 30 | 53770343259613 |
[1,1,2,5,13,36,102,299,892,2713,8364,26108,82310, 261804,838961,2706336,8780725,28636157,93818641, 308641277,1019140129,3376604826,11221805968, 37399728251,124967677989,418564867751, 1405030366113,4726036692421,15927027834163, 53770343259613] |