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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 27 |
| 6 | 84 |
| 7 | 224 |
| 8 | 712 |
| 9 | 2006 |
| 10 | 6662 |
| 11 | 19530 |
| 12 | 66075 |
| 13 | 200135 |
| 14 | 685767 |
| 15 | 2140539 |
| 16 | 7392879 |
| 17 | 23476786 |
| 18 | 82121415 |
| 19 | 264696045 |
| 20 | 931959429 |
| 21 | 3044412236 |
| 22 | 10778956363 |
| 23 | 35653064603 |
| 24 | 126785519562 |
| 25 | 422881232793 |
| 26 | 1512592426073 |
| 27 | 5085508697560 |
| 28 | 18251871593345 |
| 29 | 61808600080037 |
| 30 | 222558094522429 |
| 31 | 758833465387375 |
[1,1,2,4,12,27,84,224,712,2006,6662,19530,66075, 200135,685767,2140539,7392879,23476786,82121415, 264696045,931959429,3044412236,10778956363, 35653064603,126785519562,422881232793, 1512592426073,5085508697560,18251871593345, 61808600080037,222558094522429,758833465387375] |