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 | 7 |
| 3 | 25 |
| 4 | 109 |
| 5 | 315 |
| 6 | 1179 |
| 7 | 3234 |
| 8 | 10789 |
| 9 | 29517 |
| 10 | 89217 |
| 11 | 238422 |
| 12 | 708782 |
| 13 | 1838147 |
| 14 | 5158957 |
| 15 | 13489966 |
| 16 | 36783238 |
| 17 | 94122716 |
| 18 | 252156677 |
| 19 | 638254389 |
| 20 | 1674465026 |
| 21 | 4215683662 |
| 22 | 10834938301 |
| 23 | 27032106456 |
| 24 | 68911496918 |
| 25 | 170196098655 |
| 26 | 427274190051 |
| 27 | 1051046411165 |
| 28 | 2612004809769 |