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 | -3 |
| 2 | 24 |
| 3 | -250 |
| 4 | 3240 |
| 5 | -50421 |
| 6 | 917504 |
| 7 | -19131876 |
| 8 | 450000000 |
| 9 | -11789738455 |
| 10 | 340545503232 |
| 11 | -10752962364222 |
| 12 | 368510430439424 |
| 13 | -13623365478515625 |
| 14 | 540431955284459520 |
| 15 | -22899384412078526344 |
| 16 | 1032236014321051140096 |
| 17 | -49323481720063219673451 |
| 18 | 2490368000000000000000000 |
| 19 | -132484966403310261255807810 |