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 | 2 |
| 2 | 3 |
| 3 | 8 |
| 4 | 15 |
| 5 | 63 |
| 6 | 120 |
| 7 | 440 |
| 8 | 945 |
| 9 | 2079 |
| 10 | 4095 |
| 11 | 21735 |
| 12 | 98175 |
| 13 | 133056 |
| 14 | 395199 |
| 15 | 338625 |
| 16 | 1890945 |
| 17 | 3501576 |
| 18 | 8390304 |
| 19 | 35820225 |
| 20 | 126775935 |
| 21 | 149848335 |
| 22 | 879207616 |
| 23 | 302464800 |