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 | 0 |
| 3 | 3 |
| 4 | 19 |
| 5 | 462 |
| 6 | 18268 |
| 7 | 1410394 |
| 8 | 206677954 |
| 9 | 58152577504 |
| 10 | 31715883698744 |
| 11 | 33827568741818376 |
| 12 | 71066571962356168856 |
| 13 | 295645506683051855529248 |
| 14 | 2444503529745123468127635920 |
| 15 | 40269655263141217619540592737168 |