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 | 3 |
| 3 | 1 |
| 4 | 3 |
| 5 | 12 |
| 6 | 37 |
| 7 | 117 |
| 8 | 333 |
| 9 | 975 |
| 10 | 2712 |
| 11 | 7689 |
| 12 | 21414 |
| 13 | 60228 |
| 14 | 168597 |
| 15 | 475024 |
| 16 | 1338525 |
| 17 | 3788400 |
| 18 | 10741575 |
| 19 | 30556305 |
| 20 | 87109332 |
| 21 | 248967446 |
| 22 | 713025093 |
| 23 | 2046325125 |
| 24 | 5883406830 |
| 25 | 16944975036 |
| 26 | 48880411272 |
| 27 | 141212376513 |