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 | 2 |
| 2 | 6 |
| 3 | 29 |
| 4 | 212 |
| 5 | 2117 |
| 6 | 26830 |
| 7 | 412015 |
| 8 | 7433032 |
| 9 | 154076201 |
| 10 | 3608522954 |
| 11 | 94238893883 |
| 12 | 2715385121740 |
| 13 | 85574061070045 |
| 14 | 2928110179818478 |
| 15 | 108110945014584623 |
| 16 | 4284188833355367440 |
| 17 | 181370804507130015569 |
| 18 | 8169524599872649117330 |
| 19 | 390114757072969964280163 |