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 | 2 |
| 3 | 7 |
| 4 | 21 |
| 5 | 66 |
| 6 | 210 |
| 7 | 699 |
| 8 | 2387 |
| 9 | 8492 |
| 10 | 31329 |
| 11 | 120034 |
| 12 | 477028 |
| 13 | 1965016 |
| 14 | 8377888 |
| 15 | 36923184 |
| 16 | 167972182 |
| 17 | 787688821 |
| 18 | 3802526173 |
| 19 | 18873118341 |
| 20 | 96195592212 |
| 21 | 502953711022 |
| 22 | 2694740822749 |
| 23 | 14781176429303 |
| 24 | 82931707378322 |