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 | -25 |
| 2 | 299 |
| 3 | -1700 |
| 4 | 182773 |
| 5 | -185300 |
| 6 | 24906299 |
| 7 | -16433900 |
| 8 | 1498993813 |
| 9 | -1370832740 |
| 10 | 270199327495 |
| 11 | -103625769500 |
| 12 | 794394899339023 |
| 13 | -8895784594580 |
| 14 | 179427346755293 |
| 15 | -225134806359500 |
| 16 | -850105102171073419 |
| 17 | -248766474357466820 |
| 18 | 1778293213755999212633 |
| 19 | 141258495201145524100 |