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 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 15 |
| 5 | 93 |
| 6 | 551 |
| 7 | 4129 |
| 8 | 33607 |
| 9 | 312929 |
| 10 | 3179343 |
| 11 | 35602881 |
| 12 | 432201743 |
| 13 | 5678740945 |
| 14 | 80142780751 |
| 15 | 1210609725905 |
| 16 | 19481112885231 |
| 17 | 332836223507793 |
| 18 | 6016678424942063 |
| 19 | 114746996449871761 |
| 20 | 2302527084416470255 |