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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 13 |
| 5 | 55 |
| 6 | 133 |
| 7 | 463 |
| 8 | 1261 |
| 9 | 4039 |
| 10 | 11605 |
| 11 | 35839 |
| 12 | 105469 |
| 13 | 320503 |
| 14 | 953317 |
| 15 | 2876335 |
| 16 | 8596237 |
| 17 | 25854247 |
| 18 | 77431669 |
| 19 | 232557151 |
| 20 | 697147165 |
| 21 | 2092490071 |
| 22 | 6275373061 |
| 23 | 18830313487 |
| 24 | 56482551853 |
| 25 | 169464432775 |
| 26 | 508359743893 |
| 27 | 1525146340543 |
| 28 | 4575304803901 |
| 29 | 13726182847159 |