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 | 1 |
| 2 | -242 |
| 3 | 2883 |
| 4 | -13924 |
| 5 | 45125 |
| 6 | -115926 |
| 7 | 255367 |
| 8 | -504008 |
| 9 | 915849 |
| 10 | -1560250 |
| 11 | 2523851 |
| 12 | -3912492 |
| 13 | 5853133 |
| 14 | -8495774 |
| 15 | 12015375 |
| 16 | -16613776 |
| 17 | 22521617 |
| 18 | -30000258 |
| 19 | 39343699 |
| 20 | -50880500 |