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 | 3 |
| 2 | -23 |
| 3 | 123 |
| 4 | -623 |
| 5 | 3123 |
| 6 | -15623 |
| 7 | 78123 |
| 8 | -390623 |
| 9 | 1953123 |
| 10 | -9765623 |
| 11 | 48828123 |
| 12 | -244140623 |
| 13 | 1220703123 |
| 14 | -6103515623 |
| 15 | 30517578123 |
| 16 | -152587890623 |
| 17 | 762939453123 |
| 18 | -3814697265623 |
| 19 | 19073486328123 |
| 20 | -95367431640623 |
| 21 | 476837158203123 |
| 22 | -2384185791015623 |
| 23 | 11920928955078123 |