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 | 1 |
| 3 | 14 |
| 4 | 195 |
| 5 | 2716 |
| 6 | 37829 |
| 7 | 526890 |
| 8 | 7338631 |
| 9 | 102213944 |
| 10 | 1423656585 |
| 11 | 19828978246 |
| 12 | 276182038859 |
| 13 | 3846719565780 |
| 14 | 53577891882061 |
| 15 | 746243766783074 |
| 16 | 10393834843080975 |
| 17 | 144767444036350576 |
| 18 | 2016350381665827089 |
| 19 | 28084137899285228670 |
| 20 | 391161580208327374291 |
| 21 | 5448177985017298011404 |