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 | -4 |
| 3 | -19 |
| 4 | -55 |
| 5 | 5179 |
| 6 | 408149 |
| 7 | 23366098 |
| 8 | -2659962750 |
| 9 | -2946880278857 |
| 10 | -1715161696081878 |
| 11 | 603927037021100215 |
| 12 | 9904716216487281046207 |
| 13 | 52286804207990141325901614 |
| 14 | -71925062774291844591785748425 |
| 15 | -17522340813140430159774329947096591 |