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 | 5 |
| 4 | 15 |
| 5 | 47 |
| 6 | 153 |
| 7 | 514 |
| 8 | 1769 |
| 9 | 6205 |
| 10 | 22102 |
| 11 | 79733 |
| 12 | 290721 |
| 13 | 1069688 |
| 14 | 3966739 |
| 15 | 14810348 |
| 16 | 55627778 |
| 17 | 210046102 |
| 18 | 796864028 |
| 19 | 3035912900 |
| 20 | 11610468138 |
| 21 | 44556451207 |
| 22 | 171529074168 |
| 23 | 662238211929 |
| 24 | 2563524741603 |
| 25 | 9947573055828 |
| 26 | 38687704042595 |