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 | 1 |
| 1 | 1 |
| 2 | 70 |
| 3 | 15225 |
| 4 | 7043750 |
| 5 | 6327749750 |
| 6 | 10411817136000 |
| 7 | 29034031694460625 |
| 8 | 126890003304310093750 |
| 9 | 816448082514611102718750 |
| 10 | 7379204202189710013311562500 |
| 11 | 90369225128606332243844280406250 |
| 12 | 1457163640851863433667228849319062500 |
| 13 | 30217741884769257764596041337071409375000 |