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 | 3 |
| 2 | 11 |
| 3 | 36 |
| 4 | 132 |
| 5 | 363 |
| 6 | 1287 |
| 7 | 3548 |
| 8 | 11088 |
| 9 | 18906 |
| 10 | 111111 |
| 11 | 417972 |
| 12 | 0 |
| 13 | 3707883 |
| 14 | 12812392 |
| 15 | 37009916 |
| 16 | 128127032 |
| 17 | 368505751 |
| 18 | 1014708805 |
| 19 | 3567632391 |
| 20 | 11151642876 |
| 21 | 36657342048 |
| 22 | 104561417190 |
| 23 | 417898160427 |
| 24 | 1325269593372 |