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 | 16 |
| 2 | 84 |
| 3 | 496 |
| 4 | 3108 |
| 5 | 20176 |
| 6 | 134004 |
| 7 | 903856 |
| 8 | 6161988 |
| 9 | 42326416 |
| 10 | 292299924 |
| 11 | 2026332016 |
| 12 | 14085959268 |
| 13 | 98111307856 |
| 14 | 684331371444 |
| 15 | 4778093436976 |
| 16 | 33385561506948 |
| 17 | 233393582580496 |
| 18 | 1632228682596564 |
| 19 | 11417969833962736 |