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 | 20 |
| 4 | 51 |
| 5 | 129 |
| 6 | 307 |
| 7 | 713 |
| 8 | 1645 |
| 9 | 3721 |
| 10 | 8348 |
| 11 | 18589 |
| 12 | 41136 |
| 13 | 90619 |
| 14 | 198767 |
| 15 | 434572 |
| 16 | 947753 |
| 17 | 2062437 |
| 18 | 4480253 |
| 19 | 9718457 |
| 20 | 21055958 |
| 21 | 45575049 |
| 22 | 98566055 |
| 23 | 213028539 |
| 24 | 460160083 |
| 25 | 993533517 |
| 26 | 2144335391 |
| 27 | 4626664451 |
| 28 | 9980028172 |
| 29 | 21523027285 |
| 30 | 46408635232 |
| 31 | 100053270534 |