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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 1 |
| 4 | -21 |
| 5 | -71 |
| 6 | -45 |
| 7 | 433 |
| 8 | 1659 |
| 9 | 1513 |
| 10 | -8733 |
| 11 | -38303 |
| 12 | -45045 |
| 13 | 171289 |
| 14 | 874227 |
| 15 | 1252369 |
| 16 | -3236709 |
| 17 | -19729079 |
| 18 | -33293565 |
| 19 | 57951937 |
| 20 | 440204331 |
| 21 | 856997497 |
| 22 | -950642157 |
| 23 | -9707906447 |
| 24 | -21518582085 |
| 25 | 13107505321 |
| 26 | 211471172643 |
| 27 | 529553475361 |
| 28 | -103108955061 |