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 | 2 |
| 3 | -1 |
| 4 | -10 |
| 5 | 7 |
| 6 | 88 |
| 7 | -68 |
| 8 | -946 |
| 9 | 767 |
| 10 | 11298 |
| 11 | -9425 |
| 12 | -144024 |
| 13 | 122436 |
| 14 | 1919440 |
| 15 | -1653776 |
| 16 | -26419778 |
| 17 | 22992655 |
| 18 | 372670246 |
| 19 | -326863667 |
| 20 | -5358911450 |
| 21 | 4729547023 |
| 22 | 78264621664 |
| 23 | -69424933968 |
| 24 | -1157715304760 |
| 25 | 1031309398852 |
| 26 | 17309542787288 |
| 27 | -15474833826028 |