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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | -1 |
| 4 | 1 |
| 5 | 2 |
| 6 | -3 |
| 7 | -5 |
| 8 | 9 |
| 9 | 15 |
| 10 | -27 |
| 11 | -49 |
| 12 | 89 |
| 13 | 164 |
| 14 | -304 |
| 15 | -565 |
| 16 | 1057 |
| 17 | 1987 |
| 18 | -3745 |
| 19 | -7085 |
| 20 | 13445 |
| 21 | 25575 |
| 22 | -48771 |
| 23 | -93210 |
| 24 | 178481 |
| 25 | 342392 |
| 26 | -657935 |
| 27 | -1266205 |
| 28 | 2440323 |
| 29 | 4709403 |
| 30 | -9099507 |
| 31 | -17602325 |
| 32 | 34087058 |
| 33 | 66076421 |
| 34 | -128207979 |
| 35 | -248983641 |