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 | 0 |
| 5 | 46 |
| 6 | 702 |
| 7 | 7479 |
| 8 | 97902 |
| 9 | 1231886 |
| 10 | 15977798 |
| 11 | 208298944 |
| 12 | 3085485116 |
| 13 | 45879947392 |
| 14 | 749485746579 |
| 15 | 12963973882204 |
| 16 | 236404256556347 |
| 17 | 4415737043058504 |
| 18 | 88721524940832020 |
| 19 | 1830113429944169943 |
| 20 | 40228564066847381090 |
| 21 | 921832573196324390682 |