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 | 2 |
| 2 | 3 |
| 3 | 26 |
| 4 | 13 |
| 5 | 1074 |
| 6 | -1457 |
| 7 | 61802 |
| 8 | 7929 |
| 9 | 4218722 |
| 10 | -6385349 |
| 11 | 934344762 |
| 12 | -5065189307 |
| 13 | 141111736466 |
| 14 | 235257551943 |
| 15 | 23219206152074 |
| 16 | -97011062913167 |
| 17 | 11887164842925762 |
| 18 | -91890238533000461 |
| 19 | 4819930221202545242 |
| 20 | -14547510704199530499 |
| 21 | 1184314832978574919922 |