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 | 5 |
| 4 | 7 |
| 5 | 27 |
| 6 | 241 |
| 7 | 505 |
| 8 | 1975 |
| 9 | 10241 |
| 10 | 188743 |
| 11 | 460545 |
| 12 | 2323679 |
| 13 | 10836141 |
| 14 | 85023209 |
| 15 | 2734858573 |
| 16 | 8010483015 |
| 17 | 45714797671 |
| 18 | 243112435345 |
| 19 | 1632532938001 |
| 20 | 15831051353773 |
| 21 | 892173483721887 |
| 22 | 2978105991739613 |
| 23 | 19855526019022967 |
| 24 | 113487352591708591 |