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) |
|---|---|
| 3 | 1 |
| 4 | 23 |
| 5 | 436 |
| 6 | 8402 |
| 7 | 173860 |
| 8 | 3924685 |
| 9 | 96920092 |
| 10 | 2612981360 |
| 11 | 76612170196 |
| 12 | 2432096760755 |
| 13 | 83225580995116 |
| 14 | 3056917610828590 |
| 15 | 120045033150878404 |
| 16 | 5021755110536666777 |
| 17 | 223031850751250882620 |
| 18 | 10484575680391970139980 |
| 19 | 520227143451578652486196 |
| 20 | 27175721567427682443046975 |