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 | 1 |
| 2 | -3 |
| 3 | 10 |
| 4 | 81 |
| 5 | -4724 |
| 6 | 156205 |
| 7 | -4406814 |
| 8 | 76958273 |
| 9 | 3775676248 |
| 10 | -698309272899 |
| 11 | 72802616429830 |
| 12 | -6310377003297455 |
| 13 | 435451735391849892 |
| 14 | -10028808876450831571 |
| 15 | -4757293711381352201774 |
| 16 | 1464955115044140633346305 |
| 17 | -310063138309576689774123728 |
| 18 | 55179706013436631385620675837 |