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 | 4 |
| 2 | 57 |
| 3 | 57 |
| 4 | 421 |
| 5 | 421 |
| 6 | 1860 |
| 7 | 1860 |
| 8 | 24661 |
| 9 | 24661 |
| 10 | 380028 |
| 11 | 380028 |
| 12 | 2964603 |
| 13 | 2964603 |