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 | 1 |
| 3 | -2 |
| 4 | -11 |
| 5 | 36 |
| 6 | 421 |
| 7 | -1896 |
| 8 | -35223 |
| 9 | 201232 |
| 10 | 5188201 |
| 11 | -35856160 |
| 12 | -1188970595 |
| 13 | 9633456704 |
| 14 | 391498316301 |
| 15 | -3636762088064 |
| 16 | -175238714193967 |
| 17 | 1835360835895552 |
| 18 | 102369229796454481 |
| 19 | -1193179646751072768 |
| 20 | -75645902492063337659 |
| 21 | 971018266973866894336 |
| 22 | 68985480327663686993141 |
| 23 | -966900537026209266460672 |