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 | -3 |
| 2 | 1 |
| 3 | 6 |
| 4 | -29 |
| 5 | -74 |
| 6 | 4537 |
| 7 | 1946 |
| 8 | -23789 |
| 9 | -88434 |
| 10 | 15034541 |
| 11 | 6154786 |
| 12 | -10417027559 |
| 13 | -607884394 |
| 14 | 13199705071 |
| 15 | 80834386026 |
| 16 | -34108052679853 |
| 17 | -13923204233954 |
| 18 | 51709981061257363 |
| 19 | 3015393801263666 |
| 20 | -1029159167703800359 |
| 21 | -801997872697905114 |
| 22 | 629565265428734672873 |