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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 5 |
| 7 | 11 |
| 8 | 41 |
| 9 | 233 |
| 10 | 689 |
| 11 | 5337 |
| 12 | 49081 |
| 13 | 458299 |
| 14 | 3603685 |
| 15 | 93208147 |
| 16 | 1476087601 |
| 17 | 27470407569 |
| 18 | 816413467841 |
| 19 | 43620306030449 |
| 20 | 1172020019840081 |
| 21 | 70063780891581107 |
| 22 | 5804382690927311525 |
| 23 | 511286588817798535899 |