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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 26 |
| 4 | 390 |
| 5 | 8379 |
| 6 | 236243 |
| 7 | 8336968 |
| 8 | 357656013 |
| 9 | 18278776900 |
| 10 | 1095852254706 |
| 11 | 76105128228036 |
| 12 | 6057443479508005 |
| 13 | 547449104446315498 |
| 14 | 55722102673860207225 |
| 15 | 6341532269895314369024 |
| 16 | 801751668174625104196718 |
| 17 | 111957760296735373861748037 |
| 18 | 17178297525477106295505622856 |
| 19 | 2882568247205689424775588032950 |
| 20 | 526750240869807153027501303387666 |
[1,1,3,26,390,8379,236243,8336968,357656013, 18278776900,1095852254706,76105128228036, 6057443479508005,547449104446315498, 55722102673860207225,6341532269895314369024, 801751668174625104196718, 111957760296735373861748037, 17178297525477106295505622856, 2882568247205689424775588032950, 526750240869807153027501303387666] |