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 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 79 |
| 5 | 231 |
| 6 | 672 |
| 7 | 1951 |
| 8 | 5662 |
| 9 | 16439 |
| 10 | 47776 |
| 11 | 139025 |
| 12 | 405110 |
| 13 | 1182107 |
| 14 | 3454035 |
| 15 | 10105373 |
| 16 | 29600389 |
| 17 | 86800887 |
| 18 | 254797772 |
| 19 | 748646741 |
| 20 | 2201587214 |
| 21 | 6479524339 |
| 22 | 19084115993 |
| 23 | 56246912653 |
| 24 | 165882843095 |
| 25 | 489509315203 |