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 | 0 |
| 2 | 0 |
| 3 | 4 |
| 4 | 344 |
| 5 | 8760 |
| 6 | 157504 |
| 7 | 2388204 |
| 8 | 32737984 |
| 9 | 419969088 |
| 10 | 5141235840 |
| 11 | 60795581132 |
| 12 | 700024311536 |
| 13 | 7892352548080 |