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 | 5 |
| 3 | 1 |
| 4 | -231 |
| 5 | 81 |
| 6 | 55453 |
| 7 | -40431 |
| 8 | -30313231 |
| 9 | 33477985 |
| 10 | 29630916981 |
| 11 | -43713004191 |
| 12 | -45378051616631 |
| 13 | 83666428734513 |
| 14 | 100216964952070541 |
| 15 | -221570666935625999 |
| 16 | -301515678925659598623 |
| 17 | 777062158771833364929 |
| 18 | 1185517627245415533666277 |