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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 25 |
| 6 | 73 |
| 7 | 223 |
| 8 | 697 |
| 9 | 2217 |
| 10 | 7161 |
| 11 | 23427 |
| 12 | 77457 |
| 13 | 258417 |
| 14 | 868881 |
| 15 | 2941311 |
| 16 | 10016241 |
| 17 | 34289041 |
| 18 | 117935473 |
| 19 | 407344771 |
| 20 | 1412307481 |
| 21 | 4913508489 |
| 22 | 17148100569 |
| 23 | 60018592735 |
| 24 | 210619695913 |
| 25 | 740910077497 |
| 26 | 2612194773481 |