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 | 3 |
| 2 | 11 |
| 3 | 44 |
| 4 | 184 |
| 5 | 790 |
| 6 | 3452 |
| 7 | 15278 |
| 8 | 68290 |
| 9 | 307696 |
| 10 | 1395696 |
| 11 | 6367199 |
| 12 | 29193025 |
| 13 | 134442102 |
| 14 | 621609060 |
| 15 | 2884432810 |
| 16 | 13428450520 |
| 17 | 62703991531 |
| 18 | 293606387095 |
| 19 | 1378309455352 |
| 20 | 6485734373020 |
| 21 | 30586630485443 |
| 22 | 144544075759391 |
| 23 | 684395988590939 |