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 | -10 |
| 2 | 45 |
| 3 | -130 |
| 4 | 310 |
| 5 | -712 |
| 6 | 1555 |
| 7 | -3130 |
| 8 | 5990 |
| 9 | -11190 |
| 10 | 20316 |
| 11 | -35750 |
| 12 | 61405 |
| 13 | -103570 |
| 14 | 171730 |
| 15 | -279782 |
| 16 | 448785 |
| 17 | -710830 |
| 18 | 1112515 |
| 19 | -1720550 |
| 20 | 2632389 |
| 21 | -3989480 |
| 22 | 5992085 |
| 23 | -8921670 |
| 24 | 13176300 |
| 25 | -19316144 |
| 26 | 28118360 |
| 27 | -40654520 |