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 | 0 |
| 2 | 1 |
| 3 | -2 |
| 4 | 5 |
| 5 | -4 |
| 6 | 13 |
| 7 | -27 |
| 8 | 89 |
| 9 | -80 |
| 10 | 191 |
| 11 | -450 |
| 12 | 2365 |
| 13 | -1182 |
| 14 | 3221 |
| 15 | -13034 |
| 16 | 40433 |
| 17 | -22320 |
| 18 | 96373 |
| 19 | -193761 |
| 20 | 772981 |
| 21 | -728930 |
| 22 | 1599357 |
| 23 | -3428425 |
| 24 | 21411337 |
| 25 | -13595724 |
| 26 | 31407273 |
| 27 | -110011850 |
| 28 | 377746853 |
| 29 | -198079308 |
| 30 | 1096983421 |
| 31 | -2241234465 |
| 32 | 7565512161 |
| 33 | -6472208192 |