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 | 97 |
| 3 | -1147 |
| 4 | 3472243 |
| 5 | -653983 |
| 6 | 74118189437 |
| 7 | -1058923294571 |
| 8 | 777910456216513 |
| 9 | -285577840060819 |
| 10 | 23240203016832136201 |
| 11 | -216925341603548096639 |
| 12 | 1222007019804929270080450811 |