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 | 7 |
| 3 | 23 |
| 4 | 78 |
| 5 | 264 |
| 6 | 895 |
| 7 | 3034 |
| 8 | 10286 |
| 9 | 34872 |
| 10 | 118225 |
| 11 | 400813 |
| 12 | 1358859 |
| 13 | 4606881 |
| 14 | 15618510 |
| 15 | 52950761 |
| 16 | 179516682 |
| 17 | 608607667 |
| 18 | 2063336333 |
| 19 | 6995240208 |
| 20 | 23715661274 |
| 21 | 80402183905 |
| 22 | 272584057514 |
| 23 | 924129977596 |
| 24 | 3133038018732 |
| 25 | 10621803712455 |
| 26 | 36010643162123 |