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 | -12 |
| 3 | -39 |
| 4 | -246 |
| 5 | -1578 |
| 6 | -11487 |
| 7 | -84054 |
| 8 | -635781 |
| 9 | -4893357 |
| 10 | -38292969 |
| 11 | -303553209 |
| 12 | -2432865630 |
| 13 | -19678331838 |
| 14 | -160427322399 |
| 15 | -1316796234933 |
| 16 | -10872602692581 |
| 17 | -90242886252945 |
| 18 | -752488383572787 |
| 19 | -6300541703215803 |
| 20 | -52949782408528290 |