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 | -2 |
| 2 | 1 |
| 3 | 6 |
| 4 | -2 |
| 5 | -58 |
| 6 | -91 |
| 7 | 732 |
| 8 | 4365 |
| 9 | -1468 |
| 10 | -140682 |
| 11 | -685886 |
| 12 | 1791101 |
| 13 | 43923266 |
| 14 | 216543097 |
| 15 | -939472974 |
| 16 | -22047365454 |
| 17 | -127801626362 |
| 18 | 541608607233 |
| 19 | 16524264652568 |
| 20 | 124850392700061 |
| 21 | -279906371211584 |
| 22 | -16968403342944782 |
| 23 | -176737444660619046 |