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 | -16 |
| 3 | -179 |
| 4 | -768 |
| 5 | -2101 |
| 6 | -3680 |
| 7 | -423 |
| 8 | 32768 |
| 9 | 203095 |
| 10 | 948576 |
| 11 | 4033253 |
| 12 | 16528384 |
| 13 | 66737571 |
| 14 | 267897632 |
| 15 | 1072982449 |
| 16 | 4293918720 |
| 17 | 17178449327 |
| 18 | 68717587168 |
| 19 | 274875430845 |
| 20 | 1099508427776 |