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 | 0 |
| 1 | -1 |
| 2 | -2 |
| 3 | 44 |
| 4 | 1408 |
| 5 | -18016 |
| 6 | -5095232 |
| 7 | -139605376 |
| 8 | 56961507328 |
| 9 | 8306292414464 |
| 10 | -1178066937638912 |
| 11 | -640316054325354496 |
| 12 | -7088737339266301952 |
| 13 | 76268423227563817631744 |
| 14 | 18895160315230467816030208 |
| 15 | -12297988177132848140606242816 |