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 | 1 |
| 2 | 217 |
| 3 | 9478 |
| 4 | 185094 |
| 5 | 2185470 |
| 6 | 18188478 |
| 7 | 116799606 |
| 8 | 613592694 |
| 9 | 2745339597 |
| 10 | 10769363605 |
| 11 | 37850444632 |
| 12 | 121189368664 |
| 13 | 358136205336 |
| 14 | 987118431768 |
| 15 | 2559344776920 |
| 16 | 6286103520984 |
| 17 | 14712254089533 |
| 18 | 32974344717237 |
| 19 | 71073599975686 |
| 20 | 147860902015750 |
| 21 | 297836101312750 |