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 | 2 |
| 2 | 10 |
| 3 | 50 |
| 4 | 230 |
| 5 | 1150 |
| 6 | 5050 |
| 7 | 22310 |
| 8 | 106030 |
| 9 | 510050 |
| 10 | 2065450 |
| 11 | 10236350 |