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) |
|---|---|
| 0 | 4 |
| 1 | 13 |
| 2 | 205 |
| 3 | 2902 |
| 4 | 41413 |
| 5 | 590758 |
| 6 | 8427370 |
| 7 | 120219259 |
| 8 | 1714968133 |
| 9 | 24464596729 |
| 10 | 348995693650 |
| 11 | 4978540849669 |
| 12 | 71020558255594 |
| 13 | 1013132129923498 |
| 14 | 14452670295681235 |
| 15 | 206172198577335937 |
| 16 | 2941115696724530533 |
| 17 | 41956003773586931038 |
| 18 | 598516493115066264085 |