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 | 4 |
| 2 | 11 |
| 3 | 30 |
| 4 | 85 |
| 5 | 248 |
| 6 | 735 |
| 7 | 2194 |
| 8 | 6569 |
| 9 | 19692 |
| 10 | 59059 |
| 11 | 177158 |
| 12 | 531453 |
| 13 | 1594336 |
| 14 | 4782983 |
| 15 | 14348922 |
| 16 | 43046737 |
| 17 | 129140180 |
| 18 | 387420507 |
| 19 | 1162261486 |
| 20 | 3486784421 |
| 21 | 10460353224 |
| 22 | 31381059631 |
| 23 | 94143178850 |
| 24 | 282429536505 |
| 25 | 847288609468 |