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 | 3 |
| 1 | 14 |
| 2 | 86 |
| 3 | 560 |
| 4 | 3698 |
| 5 | 24584 |
| 6 | 164306 |
| 7 | 1103480 |
| 8 | 7444418 |
| 9 | 50431304 |
| 10 | 342941426 |
| 11 | 2340123800 |
| 12 | 16018069538 |
| 13 | 109949704424 |
| 14 | 756587236946 |
| 15 | 5217746494520 |
| 16 | 36054040477058 |
| 17 | 249557173431944 |
| 18 | 1729973554578866 |
| 19 | 12008254925383640 |