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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 8 |
| 5 | 20 |
| 6 | 82 |
| 7 | 326 |
| 8 | 1678 |
| 9 | 8776 |
| 10 | 54804 |
| 11 | 357910 |
| 12 | 2646340 |
| 13 | 20551986 |
| 14 | 176420758 |
| 15 | 1586656630 |
| 16 | 15504954504 |
| 17 | 158675287132 |
| 18 | 1738817196038 |
| 19 | 19931418239724 |
| 20 | 242312687882510 |