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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 22 |
| 4 | 83 |
| 5 | 332 |
| 6 | 1368 |
| 7 | 5795 |
| 8 | 25056 |
| 9 | 109728 |
| 10 | 487127 |
| 11 | 2183634 |
| 12 | 9876620 |
| 13 | 45013605 |
| 14 | 206392540 |
| 15 | 951751965 |
| 16 | 4410088770 |
| 17 | 20525178508 |
| 18 | 95902782437 |
| 19 | 449629623563 |
| 20 | 2114703239664 |
| 21 | 9974225860031 |
| 22 | 47168047500241 |
| 23 | 223591715338331 |
| 24 | 1062195156262639 |
| 25 | 5056231328357786 |
| 26 | 24113430736934678 |
| 27 | 115198155735233773 |
[1,2,6,22,83,332,1368,5795,25056,109728,487127, 2183634,9876620,45013605,206392540,951751965, 4410088770,20525178508,95902782437,449629623563, 2114703239664,9974225860031,47168047500241, 223591715338331,1062195156262639,5056231328357786, 24113430736934678,115198155735233773] |