This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 120 |
| 2 | 6210 |
| 3 | 153040 |
| 4 | 2224955 |
| 5 | 22069251 |
| 6 | 164176640 |
| 7 | 976395820 |
| 8 | 4855258305 |
| 9 | 20856798285 |
| 10 | 79315936751 |
| 11 | 272095118010 |
| 12 | 854560160105 |
| 13 | 2486299719645 |
| 14 | 6765755480415 |
| 15 | 17356306529251 |
| 16 | 42250330784180 |
| 17 | 98137852369965 |