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 | 5 |
| 3 | -12 |
| 4 | 27 |
| 5 | -58 |
| 6 | 120 |
| 7 | -239 |
| 8 | 456 |
| 9 | -826 |
| 10 | 1397 |
| 11 | -2130 |
| 12 | 2666 |
| 13 | -1727 |
| 14 | -4308 |
| 15 | 24597 |
| 16 | -80658 |
| 17 | 220301 |
| 18 | -544803 |
| 19 | 1259278 |
| 20 | -2760324 |
| 21 | 5775490 |
| 22 | -11553490 |
| 23 | 22039330 |
| 24 | -39774088 |
| 25 | 66751007 |
| 26 | -100238388 |
| 27 | 120817159 |
| 28 | -61934817 |
| 29 | -261953355 |
| 30 | 1315627072 |
| 31 | -4183664882 |
| 32 | 11262428169 |
| 33 | -27602763180 |