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 | 42 |
| 4 | 164 |
| 5 | 649 |
| 6 | 2592 |
| 7 | 10423 |
| 8 | 42140 |
| 9 | 171133 |
| 10 | 697641 |
| 11 | 2853587 |
| 12 | 11707542 |
| 13 | 48166629 |
| 14 | 198677283 |
| 15 | 821495226 |
| 16 | 3404577572 |
| 17 | 14140959469 |
| 18 | 58859315929 |
| 19 | 245493952745 |
| 20 | 1025954717376 |
| 21 | 4295887639272 |
| 22 | 18021572480109 |
| 23 | 75740267331717 |