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 | -1 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | -2 |
| 7 | -1 |
| 8 | 3 |
| 9 | 3 |
| 10 | -8 |
| 11 | -5 |
| 12 | 17 |
| 13 | 15 |
| 14 | -47 |
| 15 | -35 |
| 16 | 118 |
| 17 | 91 |
| 18 | -311 |
| 19 | -240 |
| 20 | 839 |
| 21 | 660 |
| 22 | -2314 |
| 23 | -1809 |
| 24 | 6417 |
| 25 | 5035 |
| 26 | -18002 |
| 27 | -14177 |
| 28 | 51016 |
| 29 | 40322 |
| 30 | -145784 |
| 31 | -115402 |
| 32 | 419197 |
| 33 | 332457 |
| 34 | -1212617 |
| 35 | -963586 |
| 36 | 3526976 |
| 37 | 2807301 |
| 38 | -10307097 |
| 39 | -8215194 |
| 40 | 30246994 |
| 41 | 24139050 |
| 42 | -89101081 |