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 | -4 |
| 1 | -2 |
| 2 | 4 |
| 3 | 22 |
| 4 | 76 |
| 5 | 238 |
| 6 | 724 |
| 7 | 2182 |
| 8 | 6556 |
| 9 | 19678 |
| 10 | 59044 |
| 11 | 177142 |
| 12 | 531436 |
| 13 | 1594318 |
| 14 | 4782964 |
| 15 | 14348902 |
| 16 | 43046716 |
| 17 | 129140158 |
| 18 | 387420484 |
| 19 | 1162261462 |
| 20 | 3486784396 |
| 21 | 10460353198 |
| 22 | 31381059604 |
| 23 | 94143178822 |
| 24 | 282429536476 |
| 25 | 847288609438 |