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) |
|---|---|
| 3 | 3 |
| 4 | 7 |
| 5 | 53 |
| 6 | 409 |
| 7 | 829 |
| 8 | 2503 |
| 9 | 27701 |
| 10 | 360337 |
| 11 | 720703 |
| 12 | 12252197 |
| 13 | 232792501 |
| 14 | 5354228843 |
| 15 | 26771144371 |
| 16 | 80313433159 |
| 17 | 2329089562747 |
| 18 | 72201776446757 |
| 19 | 144403552893563 |
| 20 | 5342931457063157 |
| 21 | 219060189739591153 |
| 22 | 9419588158802421517 |
| 23 | 442720643463713815129 |