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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 16 |
| 6 | 51 |
| 7 | 177 |
| 8 | 621 |
| 9 | 2246 |
| 10 | 8245 |
| 11 | 30783 |
| 12 | 116257 |
| 13 | 443945 |
| 14 | 1710255 |
| 15 | 6640939 |
| 16 | 25961690 |
| 17 | 102105115 |
| 18 | 403701135 |
| 19 | 1603721999 |
| 20 | 6397931901 |
| 21 | 25621989760 |
| 22 | 102965680728 |
| 23 | 415091909292 |
| 24 | 1678226164646 |
| 25 | 6803121058354 |
| 26 | 27645628327636 |