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) |
|---|---|
| 4 | 1 |
| 5 | 80 |
| 6 | 3550 |
| 7 | 125195 |
| 8 | 4009832 |
| 9 | 124266346 |
| 10 | 3854188670 |
| 11 | 121943460540 |
| 12 | 3979525634005 |
| 13 | 134806148044750 |
| 14 | 4756728585598416 |
| 15 | 175132764223880035 |
| 16 | 6731931366383154760 |
| 17 | 270129431174068396380 |
| 18 | 11308903054417009540644 |
| 19 | 493544598057755406560688 |
| 20 | 22431785171561428611320865 |