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 | -23 |
| 4 | -229 |
| 5 | -2761 |
| 6 | -42615 |
| 7 | -758499 |
| 8 | -15702086 |
| 9 | -365588036 |
| 10 | -9516954786 |
| 11 | -273061566624 |
| 12 | -8575969258607 |
| 13 | -292418459301779 |
| 14 | -10762887030763337 |
| 15 | -425243370397722674 |
| 16 | -17953905924215881215 |
| 17 | -806666656048846472309 |