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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 19 |
| 3 | 68 |
| 4 | 242 |
| 5 | 704 |
| 6 | 1981 |
| 7 | 5140 |
| 8 | 12364 |
| 9 | 27614 |
| 10 | 57598 |
| 11 | 113108 |
| 12 | 210812 |
| 13 | 375606 |
| 14 | 643646 |
| 15 | 1066196 |
| 16 | 1714445 |
| 17 | 2685464 |
| 18 | 4109493 |
| 19 | 6158768 |
| 20 | 9058119 |
| 21 | 13097592 |
| 22 | 18647371 |
| 23 | 26175300 |
| 24 | 36267330 |
| 25 | 49651242 |
| 26 | 67224024 |
| 27 | 90083308 |
| 28 | 119563302 |
[1,6,19,68,242,704,1981,5140,12364,27614,57598, 113108,210812,375606,643646,1066196,1714445, 2685464,4109493,6158768,9058119,13097592,18647371, 26175300,36267330,49651242,67224024,90083308, 119563302] |