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 | 116 |
| 6 | 672 |
| 7 | 4520 |
| 8 | 35050 |
| 9 | 303468 |
| 10 | 2934652 |
| 11 | 31145346 |
| 12 | 361323708 |
| 13 | 4535359000 |
| 14 | 61431851046 |
| 15 | 890284097146 |
| 16 | 13784350300996 |