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 | 0 |
| 2 | 3 |
| 3 | 1 |
| 4 | 27 |
| 5 | 26 |
| 6 | 385 |
| 7 | 708 |
| 8 | 7231 |
| 9 | 20296 |
| 10 | 164277 |
| 11 | 608565 |
| 12 | 4286161 |
| 13 | 19021302 |
| 14 | 123867107 |
| 15 | 617758729 |
| 16 | 3862576095 |
| 17 | 20774382552 |
| 18 | 127548675709 |
| 19 | 720773229015 |
| 20 | 4401180707397 |
| 21 | 25709943020830 |
| 22 | 157204921750191 |
| 23 | 939751281408962 |