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 | 12 |
| 3 | -327 |
| 4 | 15883 |
| 5 | -1202524 |
| 6 | 130394253 |
| 7 | -19113418989 |
| 8 | 3632485387276 |
| 9 | -867280709024131 |
| 10 | 253803272212372575 |
| 11 | -89250842789856565620 |
| 12 | 37105568909251258810585 |
| 13 | -17991614679286735149423193 |
| 14 | 10057557723279565571532112044 |
| 15 | -6417980557539322347015938082111 |