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 | 5 |
| 3 | 11 |
| 4 | 95 |
| 5 | 150 |
| 6 | 2688 |
| 7 | -111 |
| 8 | 98489 |
| 9 | -215578 |
| 10 | 4416842 |
| 11 | -18887063 |
| 12 | 230670421 |
| 13 | -1356589436 |
| 14 | 13381147908 |
| 15 | -92724422022 |
| 16 | 831047516316 |
| 17 | -6277471705749 |
| 18 | 53925750947589 |
| 19 | -426682784513559 |
| 20 | 3602138266461603 |
| 21 | -29250145766625450 |
| 22 | 245524688963062050 |