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 | 1 |
| 2 | 1 |
| 3 | -2 |
| 4 | -11 |
| 5 | -44 |
| 6 | -59 |
| 7 | -104 |
| 8 | 1513 |
| 9 | -4976 |
| 10 | 14761 |
| 11 | -1005344 |
| 12 | -594659 |
| 13 | -120135872 |
| 14 | -8409491 |
| 15 | -19661062784 |
| 16 | 461914321 |
| 17 | -4406419844864 |
| 18 | 8555830993 |
| 19 | -1268264427577856 |
| 20 | -595229416379 |
| 21 | -455779307821067264 |
| 22 | -13631036685419 |
| 23 | -200172063313066452992 |