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 | 4 |
| 4 | 13 |
| 5 | 16 |
| 6 | 61 |
| 7 | 736 |
| 8 | 1849 |
| 9 | -12032 |
| 10 | 15481 |
| 11 | 1386496 |
| 12 | 737221 |
| 13 | -139053056 |
| 14 | 8889973 |
| 15 | 22783492096 |
| 16 | 577232881 |
| 17 | -4931048505344 |
| 18 | 9090479089 |
| 19 | 1391155770032128 |
| 20 | 747609240061 |
| 21 | -492982133885763584 |
| 22 | 14533568173741 |
| 23 | 214285634326006595584 |