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) |
|---|---|
| 1 | 12 |
| 2 | 66 |
| 3 | 228 |
| 4 | 714 |
| 5 | 2172 |
| 6 | 6546 |
| 7 | 19668 |
| 8 | 59034 |
| 9 | 177132 |
| 10 | 531426 |
| 11 | 1594308 |
| 12 | 4782954 |
| 13 | 14348892 |
| 14 | 43046706 |
| 15 | 129140148 |
| 16 | 387420474 |
| 17 | 1162261452 |
| 18 | 3486784386 |
| 19 | 10460353188 |
| 20 | 31381059594 |
| 21 | 94143178812 |
| 22 | 282429536466 |
| 23 | 847288609428 |
| 24 | 2541865828314 |
| 25 | 7625597484972 |
| 26 | 22876792454946 |