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 | 3 |
| 1 | -25 |
| 2 | 563 |
| 3 | -13297 |
| 4 | 314947 |
| 5 | -7460905 |
| 6 | 176745971 |
| 7 | -4187046273 |
| 8 | 99189570819 |
| 9 | -2349764090041 |
| 10 | 55665038509363 |
| 11 | -1318684086371985 |
| 12 | 31239136201419331 |
| 13 | -740043533319442377 |
| 14 | 17531356426655688179 |
| 15 | -415311321997288071457 |
| 16 | 9838570957172556010499 |
| 17 | -233072091590971314359129 |
| 18 | 5521391278779936334581299 |