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 | 7 |
| 4 | 24 |
| 5 | 86 |
| 6 | 315 |
| 7 | 1170 |
| 8 | 4389 |
| 9 | 16588 |
| 10 | 63064 |
| 11 | 240901 |
| 12 | 923858 |
| 13 | 3554747 |
| 14 | 13716315 |
| 15 | 53054703 |
| 16 | 205651975 |
| 17 | 798645126 |
| 18 | 3106669575 |
| 19 | 12102626404 |
| 20 | 47210910670 |
| 21 | 184385864445 |
| 22 | 720920510115 |
| 23 | 2821499709615 |
| 24 | 11052719207369 |
| 25 | 43333403693711 |