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 | 5 |
| 2 | -476 |
| 3 | -19467 |
| 4 | -260848 |
| 5 | -1945349 |
| 6 | -10031040 |
| 7 | -40073671 |
| 8 | -132538112 |
| 9 | -377342793 |
| 10 | -939533824 |
| 11 | -1995150635 |
| 12 | -2982998016 |
| 13 | 2456194643 |
| 14 | 57703117312 |
| 15 | 431741625201 |
| 16 | 2752390430720 |
| 17 | 16808071568239 |
| 18 | 101361597378048 |