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) |
|---|---|
| 5 | 1 |
| 6 | -21 |
| 7 | 903 |
| 8 | -25585 |
| 9 | 875007 |
| 10 | -27125217 |
| 11 | 882215391 |
| 12 | -28005209505 |
| 13 | 899790907743 |
| 14 | -28735427761313 |
| 15 | 920460637644639 |
| 16 | -29439916001972385 |
| 17 | 942314556807454559 |
| 18 | -30150270336284213409 |
| 19 | 964869381941043396447 |
| 20 | -30874848551033891160225 |