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 | 3 |
| 1 | 135 |
| 2 | 2835 |
| 3 | 8505 |
| 4 | 12629925 |
| 5 | 492567075 |
| 6 | 1477701225 |
| 7 | 39565450299375 |
| 8 | 2255230667064375 |
| 9 | 6765692001193125 |
| 10 | 7002491221234884375 |
| 11 | 21007473663704653125 |
| 12 | 441156946937797715625 |
| 13 | 56995271759628775870171875 |