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 | 5 |
| 4 | 15 |
| 5 | 41 |
| 6 | 139 |
| 7 | 474 |
| 8 | 1773 |
| 9 | 6686 |
| 10 | 26043 |
| 11 | 101814 |
| 12 | 402297 |
| 13 | 1593124 |
| 14 | 6332329 |
| 15 | 25200575 |
| 16 | 100462874 |
| 17 | 400908688 |
| 18 | 1601541747 |