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 | 6 |
| 5 | 10 |
| 6 | 30 |
| 7 | 70 |
| 8 | 510 |
| 9 | 2590 |
| 10 | 131070 |
| 11 | 3359230 |
| 12 | 167247870 |
| 13 | 8589934590 |
| 14 | 13985925344264190 |