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 | -2 |
| 3 | -1 |
| 4 | -20 |
| 5 | -11 |
| 6 | 46 |
| 7 | -547 |
| 8 | -29840 |
| 9 | -27351 |
| 10 | 232818 |
| 11 | -3258663 |
| 12 | -29911848 |
| 13 | -390445563 |
| 14 | 4450393260 |
| 15 | -84140635815 |
| 16 | -12153983817984 |
| 17 | -18431412645519 |
| 18 | 286688710444842 |
| 19 | -6436900596281679 |
| 20 | -169286474970429624 |
| 21 | -2208721087854287811 |
| 22 | 41892263643715799796 |
| 23 | -1149793471388581053219 |