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 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 4 |
| 6 | -112 |
| 7 | -1184 |
| 8 | -9088 |
| 9 | -59504 |
| 10 | -310528 |
| 11 | -643136 |
| 12 | 14701568 |
| 13 | 323581504 |
| 14 | 4554426368 |
| 15 | 51666451456 |
| 16 | 458243735552 |
| 17 | 2004840714496 |
| 18 | -37024075153408 |
| 19 | -1386061762251776 |
| 20 | -29290212127670272 |
| 21 | -483475390212586496 |
| 22 | -6224109737622372352 |
| 23 | -45231727252157947904 |