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 | -1 |
| 4 | -4 |
| 5 | -7 |
| 6 | -6 |
| 7 | 3 |
| 8 | 21 |
| 9 | 40 |
| 10 | 40 |
| 11 | -5 |
| 12 | -106 |
| 13 | -226 |
| 14 | -256 |
| 15 | -39 |
| 16 | 519 |
| 17 | 1257 |
| 18 | 1591 |
| 19 | 592 |
| 20 | -2441 |
| 21 | -6880 |
| 22 | -9655 |
| 23 | -5365 |
| 24 | 10836 |
| 25 | 37026 |
| 26 | 57411 |
| 27 | 41104 |
| 28 | -43784 |
| 29 | -195632 |
| 30 | -335251 |
| 31 | -288787 |
| 32 | 146261 |
| 33 | 1012395 |
| 34 | 1925220 |
| 35 | 1921485 |
| 36 | -249566 |
| 37 | -5112401 |
| 38 | -10880591 |
| 39 | -12302944 |