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) |
|---|---|
| 1 | 0 |
| 2 | 4 |
| 3 | 72 |
| 4 | 3364 |
| 5 | 1700580 |
| 6 | 3743237124 |
| 7 | 44312000955508 |
| 8 | 2752746090434507556 |
| 9 | 840982281825673724760300 |
| 10 | 1273642755637661083775996170564 |