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 | -503 |
| 3 | -19656 |
| 4 | -262063 |
| 5 | -1952882 |
| 6 | -10076967 |
| 7 | -40351420 |
| 8 | -134211167 |
| 9 | -387400806 |
| 10 | -999940951 |
| 11 | -2357770544 |
| 12 | -5159248911 |
| 13 | -10602905050 |
| 14 | -20656263815 |
| 15 | -38429010468 |
| 16 | -68676430015 |
| 17 | -118458736334 |
| 18 | -197971869879 |