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 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 31 |
| 5 | 92 |
| 6 | 256 |
| 7 | 772 |
| 8 | 2291 |
| 9 | 7000 |
| 10 | 21476 |
| 11 | 66804 |
| 12 | 208935 |
| 13 | 658924 |
| 14 | 2088628 |
| 15 | 6656820 |
| 16 | 21306270 |
| 17 | 68468796 |
| 18 | 220776444 |
| 19 | 714117012 |
| 20 | 2316229821 |
| 21 | 7531561676 |
| 22 | 24545492916 |
| 23 | 80160031076 |
| 24 | 262279882239 |
| 25 | 859660694960 |
| 26 | 2822177751148 |
| 27 | 9278647613760 |
| 28 | 30547880467863 |