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) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | -100 |
| 4 | 3250 |
| 5 | -127500 |
| 6 | 5456250 |
| 7 | -241875000 |
| 8 | 10733906250 |
| 9 | -463469531250 |
| 10 | 18897269531250 |
| 11 | -699306093750000 |
| 12 | 21927485449218750 |
| 13 | -487263216796875000 |
| 14 | 923644008789062500 |
| 15 | 602420821142578125000 |
| 16 | -38171197412384033203125 |