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 | -3 |
| 2 | 29 |
| 3 | -291 |
| 4 | 3293 |
| 5 | -39715 |
| 6 | 500957 |
| 7 | -6527779 |
| 8 | 87188701 |
| 9 | -1187355427 |
| 10 | 16424527069 |
| 11 | -230141827875 |
| 12 | 3259720426717 |
| 13 | -46595454638883 |
| 14 | 671319066305757 |
| 15 | -9738441487391523 |
| 16 | 142121594825368797 |
| 17 | -2085158937761782563 |
| 18 | 30737922595101500637 |
| 19 | -455043684091275090723 |