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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 7 |
| 2 | 28 |
| 3 | 119 |
| 4 | 532 |
| 5 | 2352 |
| 6 | 10388 |
| 7 | 45913 |
| 8 | 202916 |
| 9 | 896777 |
| 10 | 3963288 |
| 11 | 17515680 |
| 12 | 77410200 |
| 13 | 342112855 |
| 14 | 1511961052 |
| 15 | 6682082183 |
| 16 | 29531331004 |
| 17 | 130513137552 |
| 18 | 576800248892 |
| 19 | 2549157374953 |
| 20 | 11265950967908 |
| 21 | 49789649104601 |
| 22 | 220044376637232 |
| 23 | 972481802150208 |
| 24 | 4297864230688560 |
[0,7,28,119,532,2352,10388,45913,202916,896777, 3963288,17515680,77410200,342112855,1511961052, 6682082183,29531331004,130513137552,576800248892, 2549157374953,11265950967908,49789649104601, 220044376637232,972481802150208,4297864230688560] |