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 | -11 |
| 2 | 143 |
| 3 | -2145 |
| 4 | 36201 |
| 5 | -675675 |
| 6 | 13777335 |
| 7 | -304008705 |
| 8 | 7204902705 |
| 9 | -182276917515 |
| 10 | 4897582264575 |
| 11 | -139156370978625 |
| 12 | 4165687398497625 |
| 13 | -130958825020098075 |
| 14 | 4311426211189071975 |
| 15 | -148272233495263502625 |