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 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 10 |
| 7 | 28 |
| 8 | 127 |
| 9 | 686 |
| 10 | 4975 |
| 11 | 42529 |
| 12 | 420948 |
| 13 | 4622509 |
| 14 | 55670332 |
| 15 | 726738971 |
| 16 | 10217376792 |
| 17 | 153848448652 |
| 18 | 2470073249960 |
| 19 | 42120966152815 |
| 20 | 760282326662191 |
| 21 | 14481561464994821 |
| 22 | 290289454462745374 |
| 23 | 6108699653117045614 |