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 | 0 |
| 4 | 744 |
| 5 | 18784 |
| 6 | 3318960 |
| 7 | 389969466 |
| 8 | 24964893804 |
| 9 | 1770631206422 |
| 10 | 143827657320448 |
| 11 | 10668015492137018 |
| 12 | 763955912402146956 |
| 13 | 55382275594728895388 |
| 14 | 4008456113318585117624 |
| 15 | 285329658478008271167456 |
| 16 | 20203324505809248032547768 |
| 17 | 1425847547641332606081597198 |
| 18 | 100103728161914529291271962728 |