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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 94 |
| 5 | 370 |
| 6 | 1537 |
| 7 | 6440 |
| 8 | 27736 |
| 9 | 120438 |
| 10 | 531524 |
| 11 | 2362294 |
| 12 | 10610448 |
| 13 | 47937526 |
| 14 | 218192951 |
| 15 | 997960740 |
| 16 | 4589673468 |
| 17 | 21193599950 |
| 18 | 98284832446 |
| 19 | 457341091934 |
| 20 | 2135427322036 |
| 21 | 9999432215682 |
| 22 | 46956175096582 |
| 23 | 221041890430474 |
| 24 | 1043005592457304 |
| 25 | 4931924148642350 |
| 26 | 23368201583344102 |
| 27 | 110925686653469910 |
[1,2,7,24,94,370,1537,6440,27736,120438,531524, 2362294,10610448,47937526,218192951,997960740, 4589673468,21193599950,98284832446,457341091934, 2135427322036,9999432215682,46956175096582, 221041890430474,1043005592457304,4931924148642350, 23368201583344102,110925686653469910] |