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 | 1 |
| 2 | 4 |
| 3 | 14 |
| 4 | 50 |
| 5 | 184 |
| 6 | 694 |
| 7 | 2670 |
| 8 | 10440 |
| 9 | 41374 |
| 10 | 165830 |
| 11 | 671084 |
| 12 | 2738334 |
| 13 | 11254362 |
| 14 | 46547340 |
| 15 | 193592830 |
| 16 | 809165002 |
| 17 | 3397135168 |
| 18 | 14319385126 |
| 19 | 60576862358 |
| 20 | 257109077584 |
| 21 | 1094541239294 |
| 22 | 4672423779086 |
| 23 | 19996407893908 |
| 24 | 85778157486910 |
| 25 | 368757697819570 |
| 26 | 1588465839532628 |
| 27 | 6855304750273902 |