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 | -7 |
| 3 | 113 |
| 4 | -2263 |
| 5 | 50721 |
| 6 | -1217703 |
| 7 | 30622929 |
| 8 | -796311415 |
| 9 | 21237226625 |
| 10 | -577699502407 |
| 11 | 15966537989425 |
| 12 | -447086291268119 |
| 13 | 12656524451911393 |
| 14 | -361628025405250023 |
| 15 | 10415207118205622673 |
| 16 | -302049007052246016183 |