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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 30 |
| 5 | 149 |
| 6 | 868 |
| 7 | 5907 |
| 8 | 46226 |
| 9 | 409105 |
| 10 | 4037904 |
| 11 | 43954703 |
| 12 | 522956302 |
| 13 | 6749977101 |
| 14 | 93928268300 |
| 15 | 1401602636299 |
| 16 | 22324392524298 |
| 17 | 378011820620297 |
| 18 | 6780385526348296 |
| 19 | 128425485935180295 |
| 20 | 2561327494111820294 |