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 | -5 |
| 2 | 15 |
| 3 | -5 |
| 4 | -5 |
| 5 | -3 |
| 6 | -5 |
| 7 | -5 |
| 8 | -45 |
| 9 | -55 |
| 10 | -143 |
| 11 | -195 |
| 12 | -1105 |
| 13 | -1615 |
| 14 | -4845 |
| 15 | -7429 |
| 16 | -185725 |
| 17 | -294975 |
| 18 | -950475 |
| 19 | -1550775 |
| 20 | -10235115 |
| 21 | -17058525 |
| 22 | -57378675 |
| 23 | -97294275 |
| 24 | -1329688425 |
| 25 | -2287064091 |
| 26 | -7916760315 |
| 27 | -13781027215 |