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 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 64 |
| 5 | 308 |
| 6 | 1727 |
| 7 | 11008 |
| 8 | 78244 |
| 9 | 611060 |
| 10 | 5184338 |
| 11 | 47366320 |
| 12 | 462782080 |
| 13 | 4807659368 |
| 14 | 52853722811 |
| 15 | 612426360832 |
| 16 | 7453621425532 |
| 17 | 94997205901940 |
| 18 | 1264555335831662 |
| 19 | 17540102647480336 |
| 20 | 252979919852470672 |