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 | -2 |
| 3 | 0 |
| 4 | 1 |
| 5 | 0 |
| 6 | 1 |
| 7 | -1 |
| 8 | -10 |
| 9 | -30 |
| 10 | -67 |
| 11 | -138 |
| 12 | -291 |
| 13 | -642 |
| 14 | -1446 |
| 15 | -3250 |
| 16 | -7244 |
| 17 | -16065 |
| 18 | -35601 |
| 19 | -78985 |
| 20 | -175416 |
| 21 | -389695 |
| 22 | -865609 |
| 23 | -1922362 |
| 24 | -4268854 |
| 25 | -9479595 |
| 26 | -21051458 |
| 27 | -46750171 |
| 28 | -103821058 |
| 29 | -230560902 |
| 30 | -512016658 |
| 31 | -1137056340 |
| 32 | -2525108865 |
| 33 | -5607619809 |