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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 41 |
| 6 | 126 |
| 7 | 386 |
| 8 | 1282 |
| 9 | 4502 |
| 10 | 16151 |
| 11 | 56767 |
| 12 | 201214 |
| 13 | 734143 |
| 14 | 2738799 |
| 15 | 10290635 |
| 16 | 38566515 |
| 17 | 145080476 |
| 18 | 553166680 |
| 19 | 2132018387 |
| 20 | 8254599276 |
| 21 | 32002694489 |
| 22 | 124412570541 |
| 23 | 486757109597 |
| 24 | 1916367227989 |
| 25 | 7571728726678 |
| 26 | 29979062727250 |
| 27 | 118957909505603 |
| 28 | 473625616693323 |
| 29 | 1892976607896793 |
[1,1,2,4,13,41,126,386,1282,4502,16151,56767, 201214,734143,2738799,10290635,38566515,145080476, 553166680,2132018387,8254599276,32002694489, 124412570541,486757109597,1916367227989, 7571728726678,29979062727250,118957909505603, 473625616693323,1892976607896793] |