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 | 19 |
| 5 | 85 |
| 6 | -29 |
| 7 | -539 |
| 8 | -365 |
| 9 | 2869 |
| 10 | 5059 |
| 11 | -12155 |
| 12 | -42509 |
| 13 | 30421 |
| 14 | 285475 |
| 15 | 102949 |
| 16 | -1609901 |
| 17 | -2227595 |
| 18 | 7431811 |
| 19 | 20797381 |
| 20 | -23793485 |
| 21 | -148577771 |
| 22 | -5816861 |
| 23 | 885649765 |
| 24 | 920550931 |
| 25 | -4393347659 |
| 26 | -9916653245 |
| 27 | 16443432709 |