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 | 4 |
| 2 | 32 |
| 3 | 220 |
| 4 | 1578 |
| 5 | 11303 |
| 6 | 81105 |
| 7 | 582032 |
| 8 | 4177161 |
| 9 | 29979239 |
| 10 | 215160247 |
| 11 | 1544201029 |
| 12 | 11082704750 |
| 13 | 79540390044 |
| 14 | 570860083491 |
| 15 | 4097053535956 |
| 16 | 29404486634726 |
| 17 | 211035522699946 |
| 18 | 1514598516808216 |
| 19 | 10870248941079889 |
| 20 | 78015599995840787 |