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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 16 |
| 4 | 40 |
| 5 | 136 |
| 6 | 328 |
| 7 | 1096 |
| 8 | 2632 |
| 9 | 8776 |
| 10 | 21064 |
| 11 | 70216 |
| 12 | 168520 |
| 13 | 561736 |
| 14 | 1348168 |
| 15 | 4493896 |
| 16 | 10785352 |
| 17 | 35951176 |
| 18 | 86282824 |
| 19 | 287609416 |
| 20 | 690262600 |
| 21 | 2300875336 |
| 22 | 5522100808 |
| 23 | 18407002696 |
| 24 | 44176806472 |
| 25 | 147256021576 |
| 26 | 353414451784 |
| 27 | 1178048172616 |
| 28 | 2827315614280 |