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 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 78 |
| 5 | 216 |
| 6 | 583 |
| 7 | 1546 |
| 8 | 4035 |
| 9 | 10320 |
| 10 | 25824 |
| 11 | 62832 |
| 12 | 146322 |
| 13 | 321876 |
| 14 | 635632 |
| 15 | 988788 |
| 16 | 958176 |
| 17 | 450280 |
| 18 | 66420 |
| 19 | 1192 |