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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 66 |
| 3 | 876 |
| 4 | 12786 |
| 5 | 197796 |
| 6 | 3183156 |
| 7 | 52718616 |
| 8 | 892401426 |
| 9 | 15368638836 |
| 10 | 268388185596 |
| 11 | 4741271556456 |
| 12 | 84573471344916 |
| 13 | 1521119577791976 |
| 14 | 27554494253636136 |
| 15 | 502257203287150896 |
| 16 | 9205363627419463506 |
[1,6,66,876,12786,197796,3183156,52718616, 892401426,15368638836,268388185596,4741271556456, 84573471344916,1521119577791976,27554494253636136, 502257203287150896,9205363627419463506] |