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 | 34 |
| 4 | 111 |
| 5 | 351 |
| 6 | 1103 |
| 7 | 3384 |
| 8 | 10224 |
| 9 | 30536 |
| 10 | 90222 |
| 11 | 264186 |
| 12 | 767663 |
| 13 | 2215623 |
| 14 | 6356907 |
| 15 | 18143300 |
| 16 | 51540885 |
| 17 | 145801395 |
| 18 | 410888595 |
| 19 | 1153964520 |
| 20 | 3230723826 |
| 21 | 9019081038 |
| 22 | 25112021154 |
| 23 | 69750583164 |
| 24 | 193303849531 |
| 25 | 534602071341 |
| 26 | 1475644537323 |
| 27 | 4065845732794 |