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 | 6 |
| 4 | 35 |
| 5 | 290 |
| 6 | 2714 |
| 7 | 27524 |
| 8 | 291073 |
| 9 | 3166124 |
| 10 | 35169275 |
| 11 | 397047529 |
| 12 | 4541672859 |
| 13 | 52510998347 |