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 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 552 |
| 7 | 2826 |
| 8 | 17080 |
| 9 | 117816 |
| 10 | 943250 |
| 11 | 7369128 |
| 12 | 63533572 |
| 13 | 603300392 |
| 14 | 6280101222 |
| 15 | 71927971040 |
| 16 | 836503868762 |