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 | -33 |
| 5 | -89 |
| 6 | 63 |
| 7 | 1079 |
| 8 | 2607 |
| 9 | -2969 |
| 10 | -34977 |
| 11 | -75241 |
| 12 | 124047 |
| 13 | 1124551 |
| 14 | 2133183 |
| 15 | -4845961 |
| 16 | -35869713 |
| 17 | -59149529 |
| 18 | 181248543 |
| 19 | 1135240919 |
| 20 | 1593237327 |
| 21 | -6572697209 |
| 22 | -35650464897 |
| 23 | -41224422601 |
| 24 | 232831381167 |
| 25 | 1110738369511 |
| 26 | 1003901296863 |
| 27 | -8095679804521 |