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 | 5 |
| 3 | 0 |
| 4 | 2295 |
| 5 | 453871 |
| 6 | 0 |
| 7 | 545539395584 |
| 8 | 4883188189089105 |
| 9 | 0 |
| 10 | 14214363393075742724609375 |
| 11 | 5968603205606800870499639536231 |
| 12 | 0 |
| 13 | 41302584753289717847206700750464023881130441 |