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 | -31 |
| 3 | -337 |
| 4 | 24705 |
| 5 | 2451679 |
| 6 | -17936543 |
| 7 | -42895630065 |
| 8 | -5396647099903 |
| 9 | 1239561882325439 |
| 10 | 708575518706816481 |
| 11 | 37448619025871342959 |
| 12 | -113842057082636742446975 |
| 13 | -52054011876398495316250977 |
| 14 | 16226448322449614832534708065 |
| 15 | 31975745831751940004484917311439 |