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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 11 |
| 5 | 59 |
| 6 | 419 |
| 7 | 839 |
| 8 | 2519 |
| 9 | 27719 |
| 10 | 360359 |
| 11 | 720719 |
| 12 | 12252239 |
| 13 | 232792559 |
| 14 | 5354228879 |
| 15 | 26771144399 |
| 16 | 80313433199 |
| 17 | 2329089562799 |
| 18 | 72201776446799 |
| 19 | 144403552893599 |
| 20 | 5342931457063199 |
| 21 | 219060189739591199 |
| 22 | 9419588158802421599 |
| 23 | 442720643463713815199 |