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) |
|---|---|
| 1 | 1 |
| 2 | -4 |
| 3 | 8 |
| 4 | 67 |
| 5 | 266 |
| 6 | 9757 |
| 7 | 47748 |
| 8 | -97258 |
| 9 | -251115 |
| 10 | 671488 |
| 11 | -4724169 |
| 12 | -28356343 |
| 13 | 125269419 |
| 14 | -498668029 |
| 15 | -5426804695 |
| 16 | 15313259790 |
| 17 | -40462770156 |
| 18 | 105160602326 |
| 19 | -4412226092528 |
| 20 | -350847041434052 |
| 21 | -54342998565206181 |