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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 8 |
| 6 | 24 |
| 7 | 108 |
| 8 | 640 |
| 9 | 4492 |
| 10 | 36336 |
| 11 | 329900 |
| 12 | 3326788 |
| 13 | 36846288 |
| 14 | 444790512 |
| 15 | 5811886656 |
| 16 | 81729688428 |
| 17 | 1230752346368 |
| 18 | 19760413251956 |
| 19 | 336967037143596 |
| 20 | 6082255029733168 |
| 21 | 115852476579940152 |
| 22 | 2322315553428424200 |
| 23 | 48869596859895986108 |