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 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 73 |
| 6 | 243 |
| 7 | 785 |
| 8 | 2504 |
| 9 | 7968 |
| 10 | 25389 |
| 11 | 81033 |
| 12 | 258873 |
| 13 | 827263 |
| 14 | 2643616 |
| 15 | 8447300 |
| 16 | 26990489 |
| 17 | 86236655 |
| 18 | 275531223 |
| 19 | 880341121 |
| 20 | 2812760102 |
| 21 | 8987010878 |
| 22 | 28714292671 |
| 23 | 91744697633 |
| 24 | 293132350135 |
| 25 | 936583428475 |
| 26 | 2992465580300 |