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 | 4 |
| 2 | 12 |
| 3 | 36 |
| 4 | 108 |
| 5 | 324 |
| 6 | 948 |
| 7 | 2740 |
| 8 | 7892 |
| 9 | 22540 |
| 10 | 64020 |
| 11 | 181396 |
| 12 | 511828 |
| 13 | 1440652 |
| 14 | 4045676 |
| 15 | 11322732 |
| 16 | 31615780 |
| 17 | 88100644 |
| 18 | 245143676 |
| 19 | 681002276 |
| 20 | 1888943100 |
| 21 | 5233741636 |
| 22 | 14484853148 |
| 23 | 40043579596 |
| 24 | 110590828396 |
| 25 | 305133547724 |