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 | 3 |
| 3 | 1 |
| 4 | -16 |
| 5 | 25 |
| 6 | 1 |
| 7 | 588 |
| 8 | -904 |
| 9 | 343 |
| 10 | 1 |
| 11 | -35108 |
| 12 | 65593 |
| 13 | -36965 |
| 14 | 6561 |
| 15 | 1 |
| 16 | 3541662 |
| 17 | -7450307 |
| 18 | 5299298 |
| 19 | -1551461 |
| 20 | 161051 |
| 21 | 1 |
| 22 | -539667860 |
| 23 | 1239476145 |
| 24 | -1027098387 |
| 25 | 393094596 |
| 26 | -70630574 |
| 27 | 4826809 |
| 28 | 1 |
| 29 | 115929493398 |
| 30 | -285126982237 |
| 31 | 264011385389 |