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 | 5 |
| 3 | 18 |
| 4 | 69 |
| 5 | 252 |
| 6 | 920 |
| 7 | 3370 |
| 8 | 12346 |
| 9 | 45207 |
| 10 | 165821 |
| 11 | 609734 |
| 12 | 2247151 |
| 13 | 8300708 |
| 14 | 30734578 |
| 15 | 114067100 |
| 16 | 424306230 |
| 17 | 1581788460 |
| 18 | 5909243454 |
| 19 | 22120325320 |
| 20 | 82963636468 |
| 21 | 311732564498 |
| 22 | 1173377033602 |
| 23 | 4424032482238 |
| 24 | 16706682557212 |