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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 168 |
| 3 | 5346 |
| 4 | 67840 |
| 5 | 496875 |
| 6 | 2544696 |
| 7 | 10151428 |
| 8 | 33693696 |
| 9 | 97135605 |
| 10 | 250525000 |
| 11 | 590412966 |
| 12 | 1291500288 |
| 13 | 2653631071 |
| 14 | 5169160920 |
| 15 | 9616725000 |
| 16 | 17188519936 |
| 17 | 29659392873 |
| 18 | 49607301096 |
| 19 | 80696066410 |
| 20 | 128032800000 |
| 21 | 198613915731 |
| 22 | 301875282808 |
| 23 | 450363792396 |