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) |
|---|---|
| 5 | 1 |
| 6 | 30 |
| 7 | 651 |
| 8 | 12600 |
| 9 | 235494 |
| 10 | 4396140 |
| 11 | 83471850 |
| 12 | 1627358040 |
| 13 | 32754696975 |
| 14 | 682573101210 |
| 15 | 14749179169725 |
| 16 | 330654317994000 |
| 17 | 7691170398011100 |
| 18 | 185559161386599000 |
| 19 | 4641068950134516900 |
| 20 | 120256269348313098000 |