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 | 0 |
| 3 | 1 |
| 4 | 74 |
| 5 | 3779 |
| 6 | 120843 |
| 7 | 2773763 |
| 8 | 51107344 |
| 9 | 805174011 |
| 10 | 11244522420 |
| 11 | 142255064793 |
| 12 | 1653293013642 |
| 13 | 17823797419169 |
| 14 | 179533887188847 |
| 15 | 1699220846514978 |
| 16 | 15182270522949405 |
| 17 | 128567147204357410 |
| 18 | 1035446619662739678 |
| 19 | 7955228396405343294 |
| 20 | 58463614912279595189 |