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 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | 1 |
| 5 | -1 |
| 6 | 3 |
| 7 | -3 |
| 8 | 1 |
| 9 | 7 |
| 10 | -13 |
| 11 | 13 |
| 12 | 1 |
| 13 | -25 |
| 14 | 51 |
| 15 | -51 |
| 16 | 1 |
| 17 | 103 |
| 18 | -205 |
| 19 | 205 |
| 20 | 1 |
| 21 | -409 |
| 22 | 819 |
| 23 | -819 |
| 24 | 1 |
| 25 | 1639 |
| 26 | -3277 |
| 27 | 3277 |
| 28 | 1 |
| 29 | -6553 |
| 30 | 13107 |
| 31 | -13107 |
| 32 | 1 |
| 33 | 26215 |
| 34 | -52429 |
| 35 | 52429 |
| 36 | 1 |
| 37 | -104857 |
| 38 | 209715 |
| 39 | -209715 |
| 40 | 1 |
| 41 | 419431 |
| 42 | -838861 |
| 43 | 838861 |
| 44 | 1 |
| 45 | -1677721 |
| 46 | 3355443 |
| 47 | -3355443 |
| 48 | 1 |
| 49 | 6710887 |
| 50 | -13421773 |
| 51 | 13421773 |
| 52 | 1 |