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 | 20 |
| 3 | 57 |
| 4 | 126 |
| 5 | 700 |
| 6 | 2569 |
| 7 | 7779 |
| 8 | 31081 |
| 9 | 117084 |
| 10 | 400727 |
| 11 | 1478944 |
| 12 | 5485580 |
| 13 | 19599269 |
| 14 | 71231855 |
| 15 | 261062287 |
| 16 | 945122754 |
| 17 | 3430304343 |
| 18 | 12504256178 |
| 19 | 45424857782 |
| 20 | 164983194009 |
| 21 | 600231458537 |
| 22 | 2182009835511 |
| 23 | 7929300624520 |
| 24 | 28830589829675 |