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 | -4 |
| 2 | 20 |
| 3 | -45 |
| 4 | 126 |
| 5 | -3066 |
| 6 | 98988 |
| 7 | -14808876 |
| 8 | 1088223045 |
| 9 | -11017349070 |
| 10 | 121040912274 |
| 11 | -2384786370947 |
| 12 | 45093873748908 |
| 13 | -140317516983756 |
| 14 | 553849385827045 |
| 15 | -4262743007968170 |
| 16 | 28759236845787534 |
| 17 | -62522995423971463 |