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 | 5 |
| 2 | 21 |
| 3 | 76 |
| 4 | 246 |
| 5 | 738 |
| 6 | 2108 |
| 7 | 5794 |
| 8 | 15458 |
| 9 | 40296 |
| 10 | 103129 |
| 11 | 260019 |
| 12 | 647617 |
| 13 | 1596800 |
| 14 | 3904260 |
| 15 | 9479292 |
| 16 | 22879520 |
| 17 | 54947836 |
| 18 | 131406732 |
| 19 | 313129592 |
| 20 | 743878505 |
| 21 | 1762572329 |
| 22 | 4167010597 |
| 23 | 9832766588 |
| 24 | 23164353834 |