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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 29 |
| 6 | 120 |
| 7 | 685 |
| 8 | 6431 |
| 9 | 103164 |
| 10 | 2894632 |
| 11 | 138892304 |
| 12 | 11118977705 |
| 13 | 1459412127955 |