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 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 37 |
| 7 | 112 |
| 8 | 363 |
| 9 | 1235 |
| 10 | 4427 |
| 11 | 16526 |
| 12 | 64351 |
| 13 | 259471 |
| 14 | 1083935 |
| 15 | 4668704 |
| 16 | 20732609 |
| 17 | 94607409 |
| 18 | 443476993 |
| 19 | 2130346450 |
| 20 | 10482534517 |
| 21 | 52740593933 |
| 22 | 271186949333 |
| 23 | 1423127827792 |
| 24 | 7618169603035 |
| 25 | 41554791114643 |
| 26 | 230857090312059 |
| 27 | 1305086617517534 |