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 | 4 |
| 2 | 112 |
| 3 | 8432 |
| 4 | 909288 |
| 5 | 121106960 |
| 6 | 18167084064 |
| 7 | 2956370702688 |
| 8 | 510696155882492 |
| 9 | 92343039606440064 |
| 10 | 17311893232788414400 |
| 11 | 3342127071364266721200 |
| 12 | 661066887819006986788620 |
| 13 | 133456726466163517072371360 |