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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 1 |
| 5 | 5 |
| 6 | 5 |
| 7 | 41 |
| 8 | 36 |
| 9 | 199 |
| 10 | 420 |
| 11 | 1377 |
| 12 | 4140 |
| 13 | 10728 |
| 14 | 36839 |
| 15 | 87400 |
| 16 | 283225 |
| 17 | 660812 |
| 18 | 1940633 |
| 19 | 4609045 |
| 20 | 12276261 |
| 21 | 29878104 |
| 22 | 73822900 |
| 23 | 181872899 |
| 24 | 428160287 |
| 25 | 1053371836 |
| 26 | 2416581766 |
| 27 | 5864707345 |
| 28 | 13309989382 |
| 29 | 31614183273 |
| 30 | 71451195226 |