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 | 2 |
| 3 | 1 |
| 4 | 3 |
| 5 | 1 |
| 6 | 11 |
| 7 | 2 |
| 8 | 65 |
| 9 | 3 |
| 10 | 518 |
| 11 | -38 |
| 12 | 5177 |
| 13 | -936 |
| 14 | 62162 |
| 15 | -17345 |
| 16 | 871204 |
| 17 | -322337 |
| 18 | 13956609 |
| 19 | -6350933 |
| 20 | 251541299 |
| 21 | -134624336 |
| 22 | 5037176913 |
| 23 | -3078652355 |
| 24 | 110952516422 |
| 25 | -75846181078 |
| 26 | 2665939046483 |
| 27 | -2007107043372 |
| 28 | 69390261389636 |
| 29 | -56857829217527 |
| 30 | 1944934425953180 |