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 | -8 |
| 2 | 20 |
| 3 | -16 |
| 4 | 58 |
| 5 | -288 |
| 6 | 424 |
| 7 | -464 |
| 8 | 2035 |
| 9 | -4816 |
| 10 | 7364 |
| 11 | -15008 |
| 12 | 32030 |
| 13 | -69152 |
| 14 | 135352 |
| 15 | -217840 |
| 16 | 460537 |
| 17 | -1012000 |
| 18 | 1704176 |
| 19 | -3043120 |
| 20 | 6200086 |
| 21 | -11737792 |
| 22 | 21029184 |
| 23 | -37602016 |
| 24 | 70312646 |
| 25 | -132822480 |
| 26 | 235883988 |
| 27 | -412277440 |